If it is not a habit the therapist has an interest in changing, then I think it is something that a client can accept, challenge every time, or decide to find a new therapist.
There are some habits I would be willing to change for a student and some I would not.

You could try looking at your phone when she clicks hers, or stop talking until she quits and tell her you will continue when her attention is back on you and that might get her attention