AITA for not paying rent for my sister's home that I'm living in.

I (30F) live in my sister and BIL's converted garage. It has a bedroom, bathroom, and a decent sized kitchenette area. <br><br>My sister bought this home 9 years ago with her now ex-husband. 2 years after purchasing the home they built the garage. I moved in 8 months ago after my sister and BIL purchased a new home.<br><br>I don't feel I should pay rent. My sister and BIL own the home outright. I believe they only have property taxes, insurance, and maintenance. My BIL isn't fond of me living here and thinks I should pay $1000 a month in rent.<br><br>I told my BIL that I will pay rent when my sister gets a job. I currently pay all the utilities and have a garden which we both benefit from.<br><br>I get a small disability check from the VA every month. I'm unable to work due to mobility issues. My sister is a homemaker, she doesn't work. My BIL thinks I should find a way to work. I don't think I'm being selfish. I will not have money to move if they decide to kick me out.<br><br>I live on roughly $900 a month. I really can't afford to pay $1000 a month. I'd essentially be getting nothing but a roof in return.