Yes. I find that you get disconnected from everyone. It becomes like talking to someone across a cliff or chasm. I'd suggest that you let her know that this is part of depression. Let her know that it can pass in time even though it doesn't seem like it. Try to empathize with her perception as best you can.
What kind of professional help is she getting for her depression? I find that an Anti-depressant can help with the disconnection because that makes it hard to do talk therapy. It is hard to focus on others let alone feel connected to another human being at that time.