I have had three greyhounds - all of them were fine with four grandkids from birth on. My last grey, Maggie, adored children of any age. I always made sure the kids were supervised when the dogs were around. All of mine were fostered prior to me adopting them (the dogs, not the kids). That way, I feel, you can get a good idea about food aggression, sleep aggression, interaction with children, etc.
Judging by my three, you will find the perfect dog for you.