I really don't think she was trying to assume anything about you...probably just wanted to be clear on what the rules are more or less. I mean when I go to therapy the therapist might ask if I've been feeling suicidal at all...not because she's accusing me of planning to attempt suicide just to check up and make sure since that is a risk. They have to tell all people they provide therapy to that they have to take action(usually call emergency services to take you to the ER in most cases) if you imply you're a danger to yourself or others....not because they automatically think that will happen but just to make sure they are informed. So I think she was just trying to be informative.

Its ok to have told her you feel offended though, if she's a therapist she should try to understand where you are coming from...it is good to be open about how you feel.