So a bigger kid used my son's car seat and i went to adjust it. I showed my mom and she said to just…

So a bigger kid used my son's car seat and i went to adjust it. I showed my mom and she said to just move the chest strap up and it will be fine. There was so much slack in the strap and I'm like umm hell no. She said I didn't have to freak out. Umm yeah I did because I know now that my mom wouldn't fix it but just let him go unsafe in her car like that.