I'm so sorry for your pain have been there as well a mental breakdown in 2013 after a dx 2012 it begin to really really impact to the point of mental breakdown in 2013. Within a matter of a few months... I would say seek the counsel of a peer specialist she needs to be validated she might take offense to delusion until everyone involves proves that it actually is a delusion. It could be depression flashback unresolved trauma that finally surfaces after being undetected since she had no previous mental health history. Keep in close contact until she is back to health and please for her sake and I know you will try not to stigmatize her so that she doesn't feel made fun of.