My gma just bought me a used one. It was a nice gesture but she got it from a random garage sale. Idk how to tell her I dont feel comfortable using it :/

It looks pretty old. Its at her house so I havent been able to fully check it out, all I did was see it for a few minutes in the garage and then I had to leave.

I have a 7 month old and a newer graco seat I bought for him a few months ago. I had mentioned I will need a second seat for my baby thats due in December. I mentioned to her I wanted to get a new one and even remember when she asked me about looking at garage sales and I said I was afraid of getting a used one because you never know if it has been in an accident.

My gma is 70 yrs old and i love her.

What do I do :/