In some ways your difficult child so reminds me of my difficult child at that age. He needed constant supervision except when he was sleeping. He stole things to the point where we just had the teacher check his backpack in and out to him at night because then he couldn't hide things.
The behavior is so constant and wearing that even though we love our children we don't always like them. It is very important to take care of you during all of this. I know that is easier said than done but it makes a HUGE difference.
Does she have an IEP at school? Has she seen a child psychiatrist or neuro-psychologist?
I am sorry you are dealing with all of this-glad you are here so we can offer support. Hugs.