You have asked a very important question that is addressed to all therapapists. As the various mental health professionals choose from among the same interventions and approaches in therapy, we also share the same code of ethics, and that is to avoid dual relationships which includes not treating a friend or family member, not bartering services for therapy, and not having or developing ouside friendships or sexual relationships with our clients.
Nevertheless, perhaps around 30% do engage in various dual relationships, often with no harm done, but not always.
Mental health therapy is not a symmetrical relationship. The client reveals his or her inner workings and secrets and the therapist usually doesn't because the focus is on the client.
Although this seems to be skewered in one direction, the therapist still emerges as a safe and attentive listener who really wants to help the client with her problems. The sessions are not meant to be a counseling resource for the therapist.
After all, she is a human being like you and a very loving and caring one at that.
If you can terminate your client-therapist relationship and wait for some reasonable time to pass, if you are both willing and able to establish a new egalitarian relationship (she cannot be on a pedastal) the it is possible that you can be friends in the future.
Other therapists might give you a different answer - an iron-clad NEVER - but I do not think this way and recognize that this can be a possibility.
I have a very interesting book that you could read, which will give you tremendous insight on the entire subject.
I wish you great success. This relationship, whether professional or friendship, seems worth having.
Move cautious but don't let it go.
I wish you great success and I am glad to hear that you have moved on.