First overnight stay

So I'm starting to consider an over night stay for my 1 year old at her grandma and grandpas(in laws). I'm not worried that she wont be taken care of or anything like that and they dont live far(10 mins give or take). It would be our first time separated for more than 8 hours and we're still breastfeeding(exclusively) with table and baby foods. I know shes should be ready for cows milk and whatnot but I cant help but worry that she wont get what she needs without bm(with a sprinkle of separation anxiety on my part). What can I do to ease my worry and make sure I'm doing everything right for my daughter as far as her needs.