When is the best time to introduce dogs with a new puppy?

I have a new puppy (yorkie) and also have two larger, outdoor dogs. I have already let the puppy in contact with the more timid dog, he’s actually afraid of her. The interaction was quick. My problem may be with my older dog. He isn’t aggressive, he just wants to sniff her and play. But she’s 4 lbs. and he’s about 70lbs. I am planning on training classes with the puppy, the other two are already good, but if a little, yappy dog is bothering them… well, they are dogs. Should I wait until the puppy has more training and will listen better? The bigger dogs are in a dog run, so they do see her when I take her out to potty and they have met through the wire fence. I take my bigger dogs to the dog park and they are fine, they always have the little ones running after them, but this one lives at thier home now. I’m only concerned because she will always be a tiny dog and I know it only takes one wrong move… Should I just wait until I have better control of her?
All wonderful advice, thank you. But I think I’m more concerned that the puppy will attack the bigger one, and he will not put up with it. She already acts dominant and I know she is going to learn that she isn’t. I just don’t want her hurt or him hating her forever. When we got our middle dog last year, ther were no problems at all. But he was a bigger puppy and he didn’t dare try to dominate the other one. I have tried bringing the older one inside to meet her, but she just barked and tried to bite him and of course, he tried to return the favor. I guess I just have to toughen up…