As far as your therapist's speculations about your childhood abuse and dissociation, they are not entirely baseless just because there are no proven facts of your specific case for her to base them on.

Dissociation is a very common defense for victims of sexual abuse. There is more than enough clinical data collected by therapists, social workers, lawyers, medical doctors to have this as a common knowledge. So, it is a fact that dissociation often takes in cases of sexual abuse, but not only in those cases. Different types of trauma can also trigger dissociation if the trauma is severe enough.

So, there is a general data your therapist uses as a basis for her speculations. It is true though that in your specific case she doesn't have enough factual information to say assertively that there was childhood abuse from which you have been dissociating. But she can still make a speculation, as long as she is clear that this is a speculation and not a fact. As a professional, she is allowed to state her opinion, but she should explain what it is based on.

Now, that aside, the main problem I see with your therapist is not her speculations about what happened in your childhood, but what she is doing about it and about your present situation now.

I repeat, since you are the client and you are an adult, you are supposed to be the only person she should be talking about. Period. It is especially important if a therapist suspects that the client is currently being abused and/or has been abused in the past and that the alleged perpetrator is still pretty much a big part of the client's life.