One rule with any dog - even a Yorkie or a toy breed - is never, NEVER leave it along with a child. Dogs are carnivores and one should remember that.
It baffles me that people even struggle with this concept. Perhaps they watched too much Tarzan or Dr. Dolittle as a child and now believe they have a mystical ability to commune with anthropomorphic dogs.
We have a rescued chihuahua mix, loves people and children, never had a single aggressive incident, has all her kc good citizen awards.
But as much as I love her she is still an animal, one whose behaviour I could never predict with 100% certainty.
So she is never left alone with children, and when we have very young children visit she is seperated from them by a baby gate into the kitchen while they play on the floor.