The dogs we had when I was quite young (2 Aussies and a Collie) were all purchased from breeders. They were all wonderful and patient dogs!
When I was a little older, probably around 8 or 9, my mom started rescuing more. She'd pull herding breed dogs on the euthanasia list and rehome them. We had a couple go through that would have been suitable for a home with kids, so it definitely is possible. I do agree that you'd better your odds by going through a reputable rescue that puts dogs in foster homes though
Or get an English Shepherd LOL! I so hope that Quinn is still around if/when I have kids. I was raised by the best dogs ever (I learned to walk by holding onto the Collie's coat to hold myself up, and he would sloooooowly walk around the house with me) and I want to give that to my kids.