ive read some good advice here, about how you should tie the loose ends up and get out. i can only wonder why this guy hasnt taken the advice. if he stays in this, its only going to get worse.
you have to leave now, the child doesnt know you, once you leave she will go back to the ex. guaranteed. he will take care of the child, as he is legally obligated to even if he is now married himself with other kids, he has to deal with it. not you!. so stop making yourself feel like your screwing the kid if you leave. its not yours. for your future sanity, get out now.
but then i read your statement about you can have her do anything you want, cause you have her where you want her right now. i think your powertripping over that right now, and using that as a excuse to stay with her and that wont last long.. your just as fucked up as her, if you stay. cause once you do, your in the back seat again. where you always have been with her.