Hmmm... I will just say we've had 7 paps and no size related injuries yet despite having a younger kid when we first got them. My dogs' breeder also has two young grandkids that visit a lot and a large german shepherd. She has only had one injury that had nothing to do with the big dog or the kids and could have happened to a much larger dog too. We also all let our dogs jump on and off the furniture as they want (oh the rebels...)
When we approached her wanting our first papillon with a little kid (<10 years) she asked to meet Josie and watch her around the dogs. She taught her how to pick up the dogs without them jumping off her chest (which they try a lot) and thought it would be fine after seeing Jo with the dogs. So far she's been totally right.
I'm NOT saying to go get one if you have little kids. I'm just saying a lot of this depends on the kid in question.