Rain on party???

Kaitlyn

So june 8th i know 3 weeks away as of right now weather is saying rain of course it can change we are doing our daughter at my mil house outside. Any suggests what to do if it rains have no back up pland my daughter's dad side is huge....and if i to do it in her house even know would be tight what to do for activities. And any suggests on snacks and food. Mixture between kids and adult i know i will do chips and pastat salad bot sure anything eles.