I think the correct one will be "She's in trouble with her excessive weight"

corrections: 1. Is this sentence OK or how would you say it? 2. I mean she is fat and it is hard for her to do daily activities. You could say it like you wrote it but that is kind of rude. Hahaha I don't think there is a polite way to say it though. Hahaha "She's so fat that she can't do anything." and "Her weight is out of control." are even ruder. Lol