welcome and congratulations both on the new pet and having a mom who's cool enough to not only let you have a snake but actually bring it home for you. my mom still doesn't want me keeping snakes and I’m 35 lol. I think that even a fuzzy mouse is pretty small for the size of that snake. I think from the pictures it could probably handle even an adult mouse without much trouble and if I were you I would try to get it eating rat pups as soon as possible.