Daughter could have some kind of stress/anxiety disorder?

I recommend taking her to a specialist and getting an expert opinion. There are many forms of anxiety disorders and it takes more factors than symptoms alone to uncover what may be happening. You can have "compulsions" without having OCD. It's all related to anxiety, compulsions are how people with anxiety attempt to regain control out of their environment when they feel out of control. They'll want to look at genetic predisposition (anxiety disorders can be ped, for instance, from a parent to a child in 30% of cases regardless of how well the parent may attempt to prevent their anxiety effecting their child). They will also look at what may be going on with your daughter in situations like school and home. They'll ask you to get an opinion from teachers or other sources that work with your child for another view, and some other things. If you find that you're not feeling like the specialist is working well for you both, try another. It's difficult to find the right one on the first try. Your child will hopefully benefit in the long run as a result of your diligence. It's not the answer for everyone but it may be a place to start. Good luck!