According to The Hollywood Reporter's sources, Heard is in talks to play Mera, the comic book love interest of Momoa's Aquaman and the future queen of Atlantis. She first appeared in the DC canon in 1963 and has powers of her own, including the ability to control water.
This being the current superhero movie shared universe climate, she may, if she signs, end up being introduced in Zack Snyder's (Man Of Steel) planned first Justice League film alongside the likes of Henry Cavill (Man Of Steel), Ben Affleck (Gone Girl) and Gal Gadot (Fast & Furious 6). Part one of the two Justice League films is scheduled for late 2017, with James Wan (Furious 7) developing Aquaman's first standalone outing for a 2018 release.
Heard, currently on UK screens in The Danish Girl, is also playing Nicola Six in the Martin Amis adaptation London Fields, which has yet to set a solid release date.