Guene,
I'm sorry you have been put in this position. I'm not in the same spot you are, but have been dealing with my daughter's father (meth head) for almost about 14 years now. We can only do the best we can. We deal with situations as they come up and do the best we can. Hopefully for you, Suzy's parents realize they can't give her the life and love that you can and stop using her as a weapon against each other. I was lucky, and even though at the beginning my baby daddy used to threaten to kidnap her and stuff, he eventually came to the conclusion that he couldn't provide for her like I could. Keep reminding them of this and maybe you can get Suzy without a fight.

Remember, no one is judging you. You are probably harder on yourself than anyone else will be. Just do the best you can.