What is the difference if I get paid thru the same agency that Medicaid would send a stranger from?

I am licensed to be a HHA. Mom has Medicaid with 45 hours of care through an agency. Why can't I take half of those hours 20 or 25? They will only give me 15 thru consumer direct. I don't understand Medicaid. I live with mom and hadn't worked in 3 years. Now that she has help 45 hours a week I can go look for a part time job but why can't I get paid for taking care of mom? She doesn't respond well to the help and most can't take care of her. I know exactly how to and try to tell them but they still don't know or don't care. Am I missing something?