Will Mom paying her daughter for doing chores she couldn't do for herself cause a Medicaid problem?

And car questions? My Mom is in a nursing home on private pay now. But the money will be gone in 2 months.
Four and a half years ago we went to an attorney for some guidance. He said the car was fine in both our names. He put a TOD on her house. Advised us to put my name on her checking account, which we did. He said she could pay me, rather than an outside service, for work at her house. I had already cut my hours at Walmart, so I could help her take care of my Grandmother before she died, so this seemed a good plan at the time. This averaged 40 hours a month at $13 an hour. I didn’t charge her for just visiting, only for working.
She began paying me to do the laundry, cleaning, bill paying, bathing assistance, errands, etc. She paid me for a year, then decided instead of paying me money for these services she would let me have her car as she didn't drive anymore. There isn't anything in writing about this work being payment for the car. She bought the car new in 2008 for $20,000 and put it in both our names then. It is worth between $12,000 and $14,000 now (depending on which blue book you use).
1. Will I have to pay back the money she paid me for the work?
2. What happens to the car? Since both our names are on the title, will half of it be considered a gift to me that I have to pay back?
3. She did buy it 6 years ago. But since her name is still on the title, I am guessing it will still be counted as her asset. I have read that in Oklahoma, her car can't be worth more than $4,500 for Medicaid purposes. So I don't know what to do since I have paid for the car with my work. Am I going to have to sell the car since it is worth over $4,500 and I can’t prove I have been making payments on it through working for her?
Any insight would be appreciated. I am trying to get all her ducks in a row before she applies for Medicaid. And I just want to know what to expect. Thank you.