I am the 24/7 caregiver for my Mom for many years. Two older siblings are her POAs. Neither lives with my mom. My brother knows nothing of her care nerds or routines, never shows any intetest in her, and never even stops to visit her anymore. Can he be revoked and can I be added on in his place ad a co-POA with my sister? My mom has dementia and she has also lost use of het dominant hand. She can no longer sign anything. I need to be able to sign for her if neither my brother or sister can be reached.