First of all, don't tell her about going to the hospital. It is unacceptable for a client to say that anyone is sick, even if she knows that she really has a problem.
Secondly, try not to let her contact anyone she suspects, don't pass on any information of anyone she suspects, and isolate her in this range. After a long time, she will divert her attention, and you will save her from further complications.
Finally, find some targeted reading materials or film and television works to show her. For example, "Double-sided tape" reflects the adverse consequences of family disharmony.
I hope my suggestion can help you a little. In short, when something is wrong, distract her.