(the correct answer to your last question is "yes, it's possible. And it's possible that the problems would be ongoing despite her being home every night".)
Can you prove that this is ALL because she goes out every night?
Nope, you can't - that's all that's really meant by the post
ETA: please, for the sake of kiddo, forget the defensiveness. It's not needed, it's not effective and can harm you a heck of a lot more than you might realize. You're not being told these things to anger you or offend you - it's solely to try and help you focus on what is really the priority here..y'know?