"She needed to be in care, and receive intensive interpersonal treatment to overcome her compulsive lying and manipulation."

If she is institutionalized, they will put her on a regime of psychoactive medications to figure out which ones will best shut her up and turn her into a zombie. The drugs will make her feel groggy and weird, and she will probably stop taking them as soon as she is no longer under supervision. What did you think that "interpersonal treatment" consisted of? Words aren't magic. You can't talk someone out of being mentally ill anymore than you can talk them out of a broken leg or cancer.