What happens if my co signer on my new vehicle pes away?

I am 20 years old I bought a new vehicle (2010) about 5 months ago and now my great grandmother (co signer) is not doing so well I pray to god she gets better but at 90 years old you never know. I thank god for her help I just need to plan adequately. I also called the finance company and they informed me that she is main and I am co signer jeez did that just make things worse?