On the dog, on the child and on the effort one is willing to put in.
2 of mine LOVE kids. One, not so much. She was never bothered nor tormented by kids, she is just jumpy and they move too quickly for her. She barks, scares them, they cry and she barks becasue their crying bothers her. She does not bite. Anyone. She is more afraid of them than anything.
If we had kids in the home I would do the work to create mutual respect and all would be well. Our grandkids are out of town so the visits to us are not frequent so not enough for anyone to get accustomed to anyone.
Hope, who loves kids, met my granddaughter for the first time when they both were just a few months old and it looked like this: