Oh, I didn't know they re-used the old Dove and just retconned a sister in for her. Well, that answers my question about why new Dove was even working with Hawxtant in the first place. I thought it was weird that some dude wearing her sister's costume popped up and she was like, "Oh hai, sure I'll work with you, total stranger-man!"
She came back from the dead in the JSA story where Extant died. He restarted the universe in his own Chaotic image and brought her back and kept her in a dungeon like all people who go crazy because the love of their life got killed, forcing them to attain God like power so they can bring them back to life then lock them up and forget about them.