Please Help I've Never Been In This Situation Before.

Hi there! I'm in a bit of a pickle and I'm not sure what to do. Here is the situation, I helped my older sister buy a car from a dealership. She had little to no credit. Nothing in her name at all. She was recently divorced and just left another abusive relationship. So she isn't on the paperwork at all. It’s all in my name. She had put down a $2,000 downpayment. She had just gotten a job and was in the interview process for another one (she had gotten that job as well). The plan was for her to make the payments with the money she was getting from work. The jobs didn't work out for very long and the one paycheck (I think, there could have been two) she received went towards herself. She has not made a single payment towards the car in the almost 7 months she has owned it. I can't afford to pay for it and it’s out for repossession. She was asked to move out of our house and she turned her location off so we can't track her or the car. I was told I could get her for theft because technically she stole the car but I can't take care of her kids. I've never done anything like this before (and trust me I will never do it again) so I have no idea what my options are. Does anyone have any advice or knowledge on situations like this?