Wow what a plateful! First, I don't see anywhere in your post regarding what her MD has advised. She needs a complete physical with blood work up and maybe more... as what is causing this could be a legitimate medical issue and not psychological.

However, it could be what you suppose.
I would suggest that BEFORE you get a professional opinion regarding her mind that the family have her create a TRUST and designate people as Trustee and also a Durable Power of Attorney and a Health Care Surrogate. This will keep the State from taking over her life and property, and keep it in the family.

Be sure to talk with her doctor when she goes, first write down, document, what she did or said when so that it won't become a shouting match in which the MD has no idea who is telling the truth.

I read you don't like drugs and I hear ya on that... I know when my dad began to "go off the deep end" we were able to figure out he needed Selenium...which balanced him right out...but you need help to figure it out I think.
Praying that it's something physical that has caused this imbalance...and that her fears and issues will be resolved.