My dog ate a berry and is vomiting?

my dog had found some berrys i have never seen before it looks like a cherry but isn't one. it looks like a grape with pits in them but has a plum-like color to it. she is vomiting and eating grass but then just throwing that up as well. i plan to take her to the vet when they open at 6 tonight but for right now in this heat what should i do? i have an 8 month baby crawling around.