I have POA for my 80 year old mother in Virginia. Can I be a paid caregiver?

Since you are POA, you need to have a lawyer look over your paperwork to see if is allowed.

Very carefully, with the full knowledge of all, with a Lawyer assisting you (her funds will pay for this) in making a plan of care. With meticulous record keeping accounting for every penny in and every country out and with labeled folders for all receipts. No way should you do this alone because anything missed could rob your Mom of care in the State she needs it in from Medicaid in future. You may believe that this care will never be needed, but it will be. And of course you are only a paid caregiver if you are doing the HANDS ON CARE. Do know that this is reportable as income in all likelihood at tax time. Again, get the advice of professionals if you are to attempt this, and do know that your salary must be commensurate with amounts allowed by law in the State where she resides.