Lois Lane dreamt that she has gained superpowers from a blood transfusion from Superman and launches a career as Superwoman.
The theme would be revisited in a 1947 Superman comic in which a pair of fraudulent magicians cast a "spell" on Lane, making her believe she has superpowers. Superman is forced to play along with the ruse for a time, using super-speed to invisibly intervene in Lane's adventures, supporting the illusion. She briefly sports a costume modeled on Superman's before the spell is "broken". A story from Action Comics has Lois actually gaining superpowers thanks to one of Lex Luthor's inventions, and launches a short-lived career as "Superwoman."
Later stories would sporadically feature tales in which Lois gained superpowers and functioned as a "Superwoman" of sorts, but all of these were, like the 1951 tale above, only temporary, with the powers wearing off by the end of the story. A typical example of this is "The Turnabout Powers" from Superman Family, where the Earth-Two Lois Lane gained powers from her husband (the Earth-Two Superman) through the unexpected effect of an exotic extraterrestrial plant Superman had brought into their home. The plant's death reversed the effect. Another example would be in the Batman/Superman: World's Finest mini-series where Mr. Mxyzptlk briefly transformed Lois into a "Superwoman" with costume and powers.
At the end of All-Star Superman #2, Lois Lane is presented with a formula called "Exo-Genes" created by Superman that allows her to have his powers for 24 hours, and she became Superwoman. During her adventures with her new Kryptonian powers, she was wooed by two superhumans named "Samson" and "Atlas", and was captured by a time-Ultrasphinx. Her powers faded away at the end of the day. Notably, her costume seemed to be exactly the same as that of the Anti-Matter Universe's Superwoman, but in Superman's colors; both outfits were designed by Frank Quitely.
A woman from the distant planet of Staryl, Luma Lynai wins the heart of Superman. Just as Superman derives his powers from a yellow sun, Lumisa derived her gifts of super-strength and flight from an orange sun. Their romance doesn't last, as Luma becomes deathly ill under the rays of a yellow sun, and Superman can't leave Earth undefended. She physically resembles an adult Kara Zor-El, with a similar costume, except instead of being blue-and-red with a pentagonal S shield, Luma's costume is white-and-green with a circular S emblem.
Crime Syndicate of America
In 1964, an evil counterpart of Wonder Woman from a parallel universe named "Super-Woman" was introduced. This Super-Woman was a member of the Crime Syndicate of America, a villainous counterpart of the Justice League from the parallel world of "Earth-Three" (vs. the Justice League's world of "Earth-One"). Super-Woman, like Wonder Woman, was an Amazon, and possessed similar powers of super-strength and flight, had the use of a magic lasso, only hers could change shape into any form she desired. The Pre-Crisis version of Super-Woman was killed as she was trying to save Earth-Three from being destroyed by the Anti-Monitor's antimatter wave.
In Post-Crisis continuity, as established in the 1998 graphic novel JLA: Earth 2 by Grant Morrison, Superwoman (and the rest of the Crime Syndicate) comes from a parallel world similar to Earth, but located in an antimatter universe (also home to the planet Qward).
Superwoman continues to make occasional appearances as a member of the Crime Syndicate, most recently appearing in storylines in the Justice League and Superman comics. Unlike her pre-Crisis counterpart, her magic lasso doesn't change shape, but releases the inhibitions of anyone tied with it (just as Wonder Woman's compels victims to tell the truth). She also possesses heat vision, as Superman does.
Taking the alias Lois Lane, Superwoman is an Amazon by birth, and has risen through the ranks to become the chief editor of the Daily Planet in 'Patriarch's World'. In appearance she resembles Wonder Woman's secret identity of Diana Prince. Superwoman irks her colleagues. For instance, the antimatter-Cat Grant once responded to the positive-matter Superman's inquiry as to her whereabouts, "probably popping little Jimmy Olsen's zits"; Cat Grant also refers to Superwoman as "Queen Bitch".
The only civilian who knows of Superwoman's secret identity is Jimmy Olsen, who, as a sexual deviant, does what she tells him in exchange for the favour of watching when she changes her outfit and receiving pieces thereof for his "disguise kit". He is so besotted that he ignores her gibes and insults, even when she taunts, "Superwoman's Snitch, Jimmy Olsen. That's what your own Newspaper calls you." -- a reference to his mainstream title of "Superman's Pal, Jimmy Olsen" (as seen in JLA: Earth 2).
Also in the Earth 2 story, her lover Ultraman hates Superwoman's frigidity towards him. Meanwhile, she is carrying on a torrid affair with Owlman, and they sneak trysts whenever they feel Ultraman is not watching. However, from his floating fortress (the antimatter counterpart to the Fortress of Solitude), Ultraman doesn't hesitate to fire warning bursts of heat vision towards them whenever he catches them together.
In 52 Week 52, a recreation of Earth-3 was shown as a part of the new Multiverse. In the depiction were characters that are altered versions of the original Justice Society of America, including Wonder Woman. The character is not identified in 52, but later in Countdown to Final Crisis, which identifies her as Superwoman of the Crime Society of America, on an alternative world which is a reversed version of Earth-2. Based on comments by Grant Morrison, this alternate universe is not the pre-Crisis Earth-Three, making this a new character unrelated to previous versions. Grant Morrison also suggests that the Earth-3 and Antimatter Superwomen both exist post-52; the Crime Syndicate and Crime Society may even have an annual get-together.
Like the antimatter iteration of the character, she is indeed both a Lois Lane and Wonder Woman counterpart, despite possessing Kryptonian abilities such as heat vision. In Countdown, she is recruited into the Monarch's army but has her eyes gouged out by Red Robin, Jason Todd of New Earth who may or may not have been carrying Kryptonite.
In Superman #349, Superman returns from an interstellar mission to find that everyone on Earth are of opposite sex. Among them are Penny White (a female Perry White), Jenny Olsen (a female Jimmy Olsen), Louis Lane (a male Lois Lane), Batwoman (a female Batman, rather than the actual character), Wonder Warrior (a male Wonder Woman), Black Condor (a male Black Canary), and Superwoman (his female counterpart) herself. Believing he crossed into a parallel universe, Superman flies back to space to find a dimensional portal, but is blocked by an invisible barrier. He notices the parallelism fails when he sees Superwoman and Clara Kent (Superwoman's presumed secret identity) are two separate people.
After a battle with Superwoman, Superlad (a male Supergirl), and Wonder Warrior, Superman figures out that his foe Mr. Mxyzptlk is behind this gender-reversed world. This was partly due to the discrepancy of Clara Kent and Superwoman being different people. However, Mxyzptlk's biggest mistake was being too vain to give himself a reverse-gender counterpart in Superwoman's rogues gallery in The Daily Planet morgue; all of Superwoman's foes were reverse-gender counterparts to Superman's foes - except for Mxyzptlk. Superman discovers as well that he was never in a parallel universe, but rather on Earth, which Mxyzptlk had altered with his magic. After using Wonder Warrior's magic lasso to make Mxyzptlk say his name backwards and thus returning to his native dimension, the effects of Mxyzptlk's magic (including the existence of Superwoman) vanish, returning the Earth to normal.
A new Superwoman named "Laurel", apparently a female version of Superman from a parallel Earth (now identified as Earth-11), appeared for the first time in Superman/Batman, and was featured an issue later. In Earth 11's alternate universe, much like in the one featured in "The Turnabout Trap!"), reversed-gender characters exist relative to those resident on New Earth: there is a Batwoman (female Batman), Superlad (male Supergirl), and a female Darkseid known as the "Dark Queen". (It is notable that in pre-Crisis continuity, "Laurel Kent" was the name of a 30th century descendant of Superman who occasionally appeared in stories featuring the Legion of Super-Heroes, and was replaced in continuity by Laurel Gand.)
In December 2007, Superwoman and Batwoman were featured in Countdown Presents: The Search for Ray Palmer: Superwoman/Batwoman #1. It features Earth-11 as part of the new DC Multiverse and presents a male version of Wonder Woman called Wonder Man, who originates from a society of male Amazons. It also depicts that world's version of Amazons Attack!
Another version of Superwoman, this one a heroic character, came about in the form of Kristin Wells, who was created by Superman comic writer Elliot S! Maggin. Wells first appeared in Maggin's Superman novel Miracle Monday, but he later introduced her in the pages of DC Comics Presents as Superwoman. The character Wells is a 29th-century descendant of Jimmy Olsen. Wells time travels to the 20th century, where the technology she had brought from the future gives her super powers. It is this iteration of the character which appears briefly in Superman: Whatever Happened to the Man of Tomorrow?
Obsessed Superman fan Dana Dearden dated Jimmy Olsen to get close to Superman, and when that didn't work she stole mystic artifacts which granted her the strength of Hercules, the speed (and flight) of Hermes, the thunderbolts of Zeus, and the sight of Heimdall. Dana donned a green-and-purple uniform, with "Superwoman" written down the leggings, and called herself Superwoman, and tried to get Superman to fall in love with her. He rejected her advances, and Jimmy called her Obsession. She vanished attempting to help Superman rescue people from a burning ship. When Superman was split into his Red and Blue energy forms, Superwoman returned hoping that one of the Supermen would return her feelings, but Maxima intervened, and used her telepathy to convince Superwoman that she would destroy Superman with her love. The telepathic illusion wore off and she would try to win Superman over again, this time in a red-and blue costume very similar to his, and claimed to be his wife. She died trying to protect him from demons, since she knew he was vulnerable to magic.
Lucy Lane first appeared as Superwoman in Supergirl #35, her costume a nod to that of the Silver Age Superwoman Kristin Wells and containing a containment field that simulated Kryptonian powers. However, Lucy's identity was not revealed until near the story arc's end. During her tenure as Superwoman, she was blackmailed by her father, General Sam Lane, into performing acts of villainy such as killing Agent Liberty, who had been spying on General Lane and Lex Luthor. (This resulted in her being the focus of the Supergirl Faces of Evil issue.) She later attacked Reactron, which tipped off readers that Superwoman was not Kryptonian (in that that villain's Gold Kryptonite power source had no effect on her). Supergirl unmasks Superwoman, and accidentally kills her by rupturing the containment field of her suit, causing Lucy's body to contort and explode.