MIL troubles

so my fiancé' mom wants to take over almost everything she takes no account that my mom will be here also from NC (I live in Oregon) but she's always saying "C is going to be on one leg and I'll be on the other!" and "I'm giving the baby his first bath" okay I don't like speaking up about certain situations but if someone is going to give him his first bath I want it to be me or my mom considering this is her first grandbaby, it will be her 5th. How can I kindly explain to her I want my mom to at least give him his first bath... I kind of feel like I have no say in this.