Mom and her caregiver are financially abused by my brothers. Any advice?

My mom is 83; has dementia and has lost all kidney function that requires Dialysis 3 days a week 4 years now. I control all of Mom’s affairs with the help of my brother and his girlfriend. Mom was in my home 3 years now in her own home across the street from my brother in another state. All is great with mom for the 4 months she has been back home with the girlfriend staying with my mom administering meds, control and prepare renal diet meals timely, transportation to Dialysis Center, Dr And hospitals, along with companionship. The caregiver receives financial aide and mom receives only her Medicare check direct deposited and her bills auto deducted for household utilities and food with a few hundred a month to spare for gas and maintenance expenses.

My brother gets the women’s cards and goes to the atm or gas station and uses their money for his needs that leaves his girlfriend with no money and my mom into overdraft at $35.00 a pop.