Mine never has her phone on her person, it isn't even in the same room. She works from home and very occasionally her home phone will ring (can hear it faintly at the other side of the house. I wouldn't accept my T having her phone on for any reason, if a family emergency is that impending I'd rather she went and dealt with that and rearranged my session than be distracted by her phone possibly ringing. Therapy is the one time I expect to be the priority of the person I'm with, that's what I pay for.