your title question ... do you talk in 3rd person in therapy....

no I did not before I was integrated. my system was one that followed the abusers code of do not tell. this resulted in my not being able to do or say anything that would lead anyone outside my body to know the others exist.

after integration sometimes I do, I discovered its normal for people to sometimes talk about their selves in 3rd person, especially if they are parents...

therapists and other treatment providers tend to ask "how are we today?
parents tend to tell their children....We dont hit, we use our words, see what mommy is doing (mommy doing the talking) can you do it too...
teachers working problems on the board.... ok we are going to compare this with that and the teacher does all the comparing / writing on the board...

one time I asked one of my therapist why everyone talks like that. he told me its normal since the dawn of time for human beings to talk this way and thats how babies learn to talk to. then had me do an activity of watching parents with their pre verbal children, and children just learning to talk. the parent says "Jane get down from there" and Jane repeats "jane down there" parent says can I hold you and child says "hold you" or children in bigger families children learn to talk in terms of us boys or us girls, ...

I was so amazed that I was the one that was different by not talking in plurals / 3rd person. after integration I actually had to teach myself how to talk like everyone else adding 3rd person words in sometimes.