Friend thinks she's being watched?

Theres a possibility that her paranoia is being exacerbated by the behavior of her parents. If her father truly is recording phone conversation that is. Regardless of whether he is or not feeling as though your being watched and video taped is severe paranoia. She needs to seek out some professional help. Sounds like the stress from recent events in her life are beginning to cause her some difficulty. You should let her know the sooner she seeks out help the sooner the relief will come.