My T went from part time to full time at place she currently practices out of, and she still doesn't have her own office. We jump between different offices for each session, depending on the day. It is always whatever office isn't in use at that time of the day. I kind of hate it! I think it would feel "safer" and "warmer" to know it was her space and all of her stuff.
She makes it a point to make me feel comfortable wherever we are, though.