My father and mother have been married for 45 years he made his brother POA. He gave him full power to include signing deed, checks etc. My fater never put my moms name on the house or bank accounts. Could my uncle sell the house and empty the bank accounts with my fathers name out from under my mom. Leaving her homeless and broke.
Please take your mom to see an eldercare attorney, most will give you a free half hour consult. It may be the wakeup call these bullies need!
Normally I'd suggest speaking to your father and asking him what provision he has made for your mother in his will; but I'm guessing that he would tell you the equivalent of not to worry your pretty head about, or, worse, would be indignant that you dared to ask. All the same. The power to guarantee your mother's financial security, and to reassure her now that provision has been made for her, is currently in your father's hands. Do you trust him to make sure she's taken care of?
Perhaps mom wants a divorce. That would be a way for her to force equitable division assets.