It is always difficult when someone we care about distances themselves from us for no apparent reason and it is even more difficult when it is a child. Trust that she will share with you what she needs to when she is ready. Realize too that her distancing herself may have more to do with her than you. It may be her way of growing up and becoming an adult. Give her space but keep letting her know that you care about her by doing normal things. If it is an ocassion where you would normally send a card or an e-mail to her, do that, but don't expect her to recipricate. When you start to worry or stress about what is going on with her, think loving thoughts about her, imagine her surrounded with your love. Things will get better, give it time.