Can I be my mother's POA and get paid to take care of her through SS?

Seems like there might be some confusion here about what you are asking. I don’t think SS actually pays anything directly other than Medicare premium and then the recipient (your mom) but she can use the SS benefits she receives each month to pay anyone she chooses. If you mean Medicaid that will vary state to state, some states have specific programs for just this purpose and others won’t allow family to be paid with state or federal funds (her SS is treated like income, not earmarked for anything specific other than to live on). This is the way I understand it anyway.

Yes you can in CA

Some state Medicaid programs will not pay a POA or legal guardian. But your mom is free to pay you.

Social security and Medicare do not pay family caregivers. If your parent qualifies for Medicaid, you can check with your state to see if they pay family caregivers.