My understanding is that it has nothing to do with legal residency or permanent address of the client. The laws I'm aware of state that the therapist must be licensed in the state where the client physically is during the therapy session. Some laws were relaxed during COVID, some states have flexibility around people temporarily being out of state, some federal agencies (like the VA) cut across state lines, and some states have agreements with other states to honor their licenses (this is increasingly happening).

It sounds like either she ought not to have agreed to this in the first place, or like the relaxing of restrictions around COVID have been reinstated. Regardless, it's crappy, and I'm sorry you're going through this. It's so hard to find a therapist you click with, so I can understand not wanting to start over. I don't really have solutions, just lots and lots of empathy!