Hello, I also starting pulling my eyeslashes out at that time and now I still do, while in college. I can honestly say that I believe that I pulled was because I was under a lot of stress or when i felt alone. It was a release of all that after I would pull. I can't say that's the reason your daughter did but I can say that she needs to know that you care about this problem and just that you believe her and love her no matter what. That's what I wished my mom would have told me.
Good luck and I hope I was helpful