My great dane just ate 6 or so red grapes!!!?!?

I was eating some frozen red/purple grapes and my idiot self gave my great dane 6 or so grapes. I didn't even think about what I did until 10 min after I had given her some. Should I be concerned? My boyfriend's grandfather gave our other dog some raisins in the past and he had no reaction. That dog was overweight at 85lbs and my great dane is 120+ lbs. She loves ice and I didn't even think about them being grapes...I am such an idiot. Call a vet or wait it out? How long does it take for poisoning symptoms to manifest?