grandmother who acted as nanny should pay rent?

so  for the last 4 years I have  cleaned my daughters hour 15-25 a hours out the week which in excludes cleaning toilets, taking out garbage washing and putting up and picking all clothes cleaning alt he bedrooms kitchen and  taking children  for parks  movies walks .  I started as well working more with my grandson who has special needs ( now that i Have gad to live with them for the last 3 months but the cleaning and the rest started 4 years ago, in return she gave e use of the car and paid cell phone bill and put me on her car insurance with her husband ( yes he messes up also and cleaned and pick up his underwear and cloths also. So again I had  time to go any where just picked my son up from work ,no car needed it was form my home, and back and grocery store ( three of those years I had my own job as well as working at her  house) , so the car was never used by me to do fun things just essentials and her errands really. If the car need registration I paid,now that the car is paid off I am buying it form her for 1500. My question is my unemployment came and she wants  more than  the 1500 for the car. But what about all the work should I owe her rent, I bought my own food? I feel like I slaved if all of those hours or work was for not like I owe her back rent  ..what do you think should I owe her back rent for the last three months and  did I do too much for use of a car bill being paid?