I am a fairly new Yorkie owner... She is only 11 weeks old. I can answer a couple of questions for you.
First of all, a Yorkie is a very small dog, and a puppy is even more delicate. What I have read and heard is that young children and Yorkie's are not a good match.... I have read that a child under the age of 7 is too young for a Yorkie, just because of the nature of the dog, and that they are delicate.
A male or female dog is more of a manner of preferance. They both make excellent pets.
I have seen Labs that are extremely gentle and nuturing. I have witnessed a 150 lb. female lab mother a 7 week old kitten. They can be great at it . However, I would not ever leave them alone together though.
I love my little Yorkie, and have found great joy in owning her. All young children are not the same , and can be taught how to handle a very small little puppy. I would be exceedingly cautious though and make the wisest decison that best meets your family's needs, as well as a very tiny puppy.
Best of luck !