Wow,Im impressed that you had the courage to ask your T if she ever got depressed.....and she gave such a great answer too.
It feels comforting when T discloses personal stuff....even if its small.My T disclosed to me that he has a cousin who is severly mentally handicapped and what a painful ,difficult thing it was for his aunt and uncle and family.This comforted me because I have two sisters greatly mentally hadicapped.....it helped to make me feel less alone and different.
I usually make eye contact unless Im very uncomfortable talking about the subject.My T also has very very baby blue eyes and although he tries hard to mask his feelings his eyes are very reactive.I watch them when Im entering a tenuous subject.