I would say she has some anxiety issues and all you really can do is reassure her that you love her no matter her age and will always love her no matter what! Also maybe get her into some extra curricular activities such as dance,gymnastics,softball etc where she can start building friendships and not have so much time to sit and worry and dwell on things.....being part of a team will help with anxiety by giving them skills of working together and being there for one another and helps build friendships and character along the way... Maybe she needs a little push to get involved but I think it will help you both out in the long run! Good luck!