She sounds as if shes in need of a friend just like you to worry about her !!! I think it is very nice of you to be so concerned.
She is focusing i think on the man, who in her heart of hearts is unobtainable ( for whatever reason, altho i guess hes married ) because it gives her something to think about other than her life which she is struggling to get a grip on.
Its times like this i think , ones inner strength shows and at some point she will find hers, just not quite yet...................... be there for her, kindly tell her what you believe and try and ensure as much as you are able to keep her safe.
And then let her travel her path, knowing she has you to pick her up and let her find her way back.
good luck