You can't judge a dog by it's breed. It's all in the breeding and the treatment of the animal. I owuld be more leary of small dog than of a pitbull. I know of many kids that have been bitten by small dogs, but you don't hear about that on the news.
Pits got a bad rap because because they will do anything for their owner. And some bad people used this to their advantage when they started using them in fighting. It's very sad.
But it sounds like this is a wonderful pit and will be just fine with the kids.
My daughter has a friend with a pit. They brought him to my grandson's 1 yr birthday party with babies crawling all over he pace, probably 8 kids under 2 there. The pit was glorious with the kids. Gentle and kind.