Safe for children?

I live in the northeast and found a garden snail outside. I created an enclosure for it to keep as a pet. I bought creature soil and terrarium moss from a pet store. My four year old was so excited and wanted to hold the snail, so we let her and had her wash her hands after.

My mom freaked out about us having a pet snail saying that they carry parasites and salmonella and that it’s not safe for us to let my daughter touch it.

Is it possible that after having it for a while in a controlled environment that there would be no risk for any bacteria/parasite ? Is she also overreacting ? ( I hope so)