Is she suffering from depression?

Im very concerned for my friend who is displaying odd behaviour. It all started when she went to Camp in the USA to work with children. She injured her back and had to come home early and understandably she was gutted. I was very concerned as I was told she was in a lot of pain but could still move around. She has totally cut me out of her life, she wont return any call, text or email while I have assurances that she is keeping in touch with other people. I asked via text what was happening with her situation and she suddenly started displaying behaviour as I can only desbribe as someone hitting the self destruct button. Complaining that she did not have enough space and she wanted some peace and quiet. The point is I cannot really smother her as I live hundreds of miles away from her. I was fine with that until she cut her phone line off and is now not talking to anyone. Im concerned for her, I have never seen her like this and I always thought she could rely on me. Does she just need time to get back to normal or is she showing symptoms of depression? Where she lives at the moment, she doesnt have many friends because she moved up there 2 years ago and has had lots of problems trying to fit in. All of her close friends live in the main city which is very far away from where she is. I would be grateful if someone could shed some light on what they think about this, I want her to get better but I dont want to lose the friendship I have with her. That is what Im most scared of, and the way she knocked me back has startled me. Steph xx