Wow... this thread! Why is it okay for a T to question motives for behaviors, needs, and desires in every area but sexual orientation? I think your therapist is wise and brave for giving you that thought to think about.

Personally, I think people can have an innate sexual desire for the same sex, or can be pushed that direction by trauma. For your therapist to not raise the topic would be to assume you are in the first category, and assumption does not make for a good therapist. Talking about it, thinking about it, and examining how your trauma could possibly have affected your sexuality will help you understand yourself better- and THAT is her job.