well considering theres ethics laws about how much time must pass before clients and therapists can have a friendship (usually a year sometimes 2 depending upon each USA state from the last therapy contact) I would have to say 2 different answers. yes if the time was right where I would not expect her to act as a therapist and if enough time has passed from the last therapy contact, I have no problem with this at all.

I have also done so with a few of my past therapists on facebook, twitter and just meeting up out in public. having a friend relationship with past treatment providers is perfectly acceptable and the ethics laws take that into consideration. just make sure that both involved know what to expect and what you want out of the new friendship.

keep in mind also that it works the other way too. in order to go from a friend relationship to a client therapist relationship a certain amount of no contact for that past relationship before the new one begins, has to happen.