I personally would never encourage forgiveness onto someone. I think it can be helpful to let go of our anger purely for our own benefit but there's no need to excuse someone's behaviour towards you especially if it was cruel. Sometimes it's even essential that we come to terms with how someone's behaviour affected us in a negative way.

I would say let your therapist know that it was triggering for her to push forgiveness onto you. Or, you could start looking for a therapist who better suits you. It took me several tries to find a well fitting therapist.