So a few years ago when I still had decent credit, I signed on a car to help my sister out (only my name because her credit was in the abyss)with the promise that she would pay it no matter what happened. After a while, she got the first month behind. Eventually one month turned to 2, then 4. She got so far behind that I was left with no choice but to have it repossessed as I could not afford it on top of my existing car payment, and the bank was already threatening repossession themselves. Now I'm 22k in debt at collections. My sister refuses to pay any of it, and now she won't even speak to me. I have text messages from her swearing she would get it caught up and pay it on time, but that never happened. Would this hold up in court? Or would they rule in her favor since it would be considered a gift under legal definition (at least as far as I'm aware)?