Mom as baby sitter??

Ok, it has been pretty much set in stone that my mom will be the babysitter for my baby boy however the more I look at her "grandparenting" with my nieces I don't know if I want my baby to be influenced by that. For instance, she feeds snacks and juice all day to keep them quiet, she hardly ever discipline, plus she allows them to scatter their toys all over while she comes behind and clean later. Don't get me wrong I understand that's she is GRANDMA and it's her job to spoil but sometimes it's ridiculous. I want my baby boy to be spoiled BUT have some type of discipline! Because she's so easy going with my nieces they end up giving their parents a hard time because they are so use to having things their way at Grandma's. My mom adores her grandkids and I get it but I cringe at the thought of baby dj constantly being in that type of environment. Am I overreacting? Is she only doing what a grandma is supposed to do? Should I cut her slack? Or should I look into another caregiver/babysitter for my baby?