Introducing Babe to Bottle

Hey all! My husband and I are going to a wedding in September and since it’s a no kids event, I will be leaving my daughter with my mom overnight. She’ll be one week shy of 6 months and won’t be consistently eating solids. She is exclusively breastfed. I have a bit of a freezer stash going because I knew this was coming. But I have no idea how to go about giving her a bottle. I don’t want my mom to have a hungry baby with her who won’t take a bottle. I’m thinking I might start giving her one to get her used to it? But I don’t know how much to give her? I’d appreciate any thoughts or guidance you can offer!