I think you would be mad to do it. I have a 4 and a half month old golden retriever, had him since he was 9 weeks old... and his favorite thing to do in the world is bite everyone as much as possible. Even if you hold a toy for him, he will go for your arm, face, body, anything... and I don't mean a few bites here and there, I mean if you are in the same room as him, you are being bitten... hard. I would never allow him around children at this age. He is starting to calm down on the biting a bit now which is normal for the breed, but he still makes up for that with jumping up and being so boisterous. Imagine a toddler that can run at 15mph, jump, is far smarter than you expect, has 28 very sharp teeth, and enjoys nothing more than biting humans.
I'm usually a very calm person, but I've lost it so badly that I kicked in part of the kitchen one night before calming down. I knew a puppy would be hard work but they really do test you, and they know they are doing it as well. I wouldn't feel at all safe with him being around young children at this age, he has a heart of gold but not the knowledge or self control and he takes a whole lot of looking after as well, as he requires a lot of time and attention, which couldn't be shared with a young child.
Another thing he enjoys when people aren't about is destroying our house. He has ripped up most of the lino flooring in the kitchen, torn the insulation out of the door frame, ripped most of his beds to shreds, bitten through a lot of the kitchen units, and dug up most of our garden/eaten the decking. It doesn't matter how much we walk him, or that he has probably almost every toy ever created. I've learned the real meaning of the expression 'like a dog with a bone', they are obsessive and relentless.
Puppies also poop about 5 times a day and young kids learn to explore by putting things in their mouths.
I'm sure some people have managed it and it probably depends on the size of the house, resources, and how many people are helping, but I wouldn't bring up a young kid and a puppy at the same time for all the money in the world.
My brother also recently(ish) brought up a puppy and it was just as bad as mine, from what I hear of other peoples, we have been very lucky with ours so far.