Kathy, You are the one that knows her best.

If you are concerned about her right now, then you have every right to be. Not talking is not good ! I can understand you worry that she could be going through a depressions !

I would watch her closely and get her to talk about her new job, which is great ! Good for her ! Or maybe you should just go ahead and ask "is something bothering you?"

Maybe she feels it is too much for her ? and won't do too good on the job ? Maybe she is stressed about it ? Or maybe it is the build-up of many of the things that happened in the last year ?