Is there a legal way to be set paid for caring for my mother in law in our home 24/7 and is a durable power of attroney legal

I get paid 50.00 a day and care for her 24/7 .She has dementia and can not be left alone. I do her bath, and everything she needs. She walks but sometimes needs help with that. She has bowel movements in her pull ups and sometimes I get up at 2 in the morning to bathe her because she goes through the pull ups and all over everything. My husband got a durable power of attorney signed by her in the presence of notary for financial and one for medical. Are they legal and binding? She has dementia. and we wonder if that will make the durable power of attorney null and void. Also how do we know how much to charge her? 50.00 a day is not enough really when other care givers get so much and she lives with us too.