In addition to the other problematic things people have noted, I am wondering whether all these rooms have doors that close. Could her brother hear what one or both of you were saying during your session? Having to wonder who was listening in would really bother me.

Her unprofessionalism and lack of boundaries are really throwing you all over the place emotionally. I can see where you're trying to accept the unacceptable by contorting your feelings and perspective, and it's not good. Given what you have said before about your background and childhood, you're already being retraumatized in this relationship.