As someone who has had a malicious coworker do this to me and then openly slandered my name and other coworkers names, I have no sympathy. People lacking self control alongside overinflated self entitlement and lack of accountability do not belong in healthcare, or at least in roles that afford privilege and potential abuse of power.
You seem conscientious and trustworthy, loyal, and for those virtues you should consider honoring yourself, advocating for yourself, by distancing from this person. Your first loyalty should be to yourself, and that requires discernment. I feel your moral distress in this situation; she has not only violated coworkers privacy but also your sense of integrity by seeking you as a support person. That is fundamentally wrong and says volumes about her.
Keep up the good work. You seem like a coworker we would all benefit from working alongside. I apologize (to you) if my opinion seems harsh, I just know how violated, literally, the violated persons feel in this unprofessional situation.