For me the easiest/best thing is we live by my rules and I know what works for her, we have such a close bond and it feels good that she loves and wants me and doesn't know who he is, because he isn't worthy.
The worst thing is not having a break from things, just simple things like not being able to have a shower, nipping out to the shops, exercising, cleaning the house etc. When she is ill/playing up and she only has me, that is hard sometimes, especially when I am feeling low myself.
Having said that, I wouldn't have it any other way now, when she was with her daddy, she was subjected to daily arguing, him hitting me, the potential danger of her dad being drunk. I would rather not have a minute to myself than put up with that again.