Aquawoman is a reversed version of Aquaman. She is a native from earth 11 and a member of the Justice Guild and the Justice Incarnate. Originally she appeared in Countdown Presents: The Search For Ray Palmer: Superwoman/Batwoman, but after Flashpoint, a revised version became canon in The Multiversity #1.
Biography
The Multiversity
Aquawoman was among the heroes summoned to the Monitor Satellite a.k.a. the House of Heroes, when the hero from earth 7, Thunderer asked for help to rescue the Monitor Nix Uotan from the forces of the Gentry. Aquawoman traveled with the heroes to earth 8 where they found a corrupted Nix Outan. Between her and Thunderer they broke the grasp of the Gentry over Uotan and joined to the multiversal forces against the attack of the Gentry. She later accepted the invitation from President Superman from earth 23 to join the Justice League Incarnate and prevent the next attack of the Gentry and their master, the Empty Hand.
Rebirth: Multiplicity
Aquawoman, along with the rest of the Justice Incarnate helped the rebirthed Superman to save the different Supermen from several earths from the being known as Prophecy.
Alternate versions.
On the new52 version of earth 2, another character called Aquawoman resides. Called Queen Marella, she was one of the survivors from the destruction of the original earth.
An evil version of Aquawoman appeared on Batman: the Drowned, from earth -11, from the Dark Multiverse. This Aquawoman , as queen of Atlantis, attacked the surface world and drowned it causing the death of the whole world. She was killed by an enraged Batwoman, known now as the Drowned, who altered herself to breath underwater and take revenge for the death of her lover Sylvester Kyle.
Powers and Abilities
She presumably has similar abilities to Aquaman: the ability to breath and move easly underwater, a superhuiman durability and strengh. She also has show the abilitity to communicate and control aquatic lifeforms.
She has been seen using a sword and a pentadent in similar fashion as her male analogue.