I have a 5.5 pound female Yorkie. I also have an 18 months and a 4 years old. They are doing great together and are actually great friends... But here is how I did and still do it to prevent any damage.
I had Bikini when she was 11 weeks. My youngest was 10 months at the time and the other 3. I made sure I was always around when Bikini was little. She weight 2 pounds when I got her. As she was growing and the kids too, they learnt to play with one another. And I inforced respect on both side. Bikini is not the number one in the house. She knows she has to respect humans. My husband is the pack leader, then me and my two sons.
She cannot jump on kids and she learnt quickly to react to kids movement... I trained her really well and she never bites or nothing. She is quite patient. The trick with her... she is a fast runner. So most of the time, no kids can catch her and she hides behind the couch or any furniture. She thinks its a game and the kids too. It really cute.
Anyway, its possible to have kids with a Yorkie, but the parents have to be extremely vigilent...
Bikini got sick at 5 months... not because of my kids but because of adults that gave her treats under the table such as sausage, cheese and turkey. She had pancreatitis and almost died... (Trust me the adults involve know who they are and felt really bad... they always had big dogs! They did it without me knowing)
They are just tiny and fragile. Adults can do as much damage as kids can... You have to be aware and watch out!
I truly am passionate about this breed and I think with careful parents, its possible! But this is my opinion
I know there are others Yorkie Talkers that have younger kids with their Yorkie because we had a thread on this subject before. The #1 rule of thumbs is to watch out carefully and prevent any problems.
Good luck on choosing your breed!