We have the perfect living situation for a family with small children. We live beneath a family with a dog.
Her name is Gaia, and the kids absolutely adore her. We adore her too, in part because it means the kids get a dog to play with and talk about while we don't have to take walks and pick up excrement. I love dogs; but I do not have the time and energy to care for one right now. Strangely enough, it's what many think about kids. (Or should. There are a few parents I know who don't spend the time and energy, but have kids anyway. Which is sad. At least a neglected dog would bite them.)
For us, it's one of the big perks of living where we do. From the kids' perspective, I think it is the one big perk. (The other being the ability to check the mail. I have strange children.)
Families with children, I highly recommend finding a part time dog as we have. Perhaps families with dogs could also benefit from our example. I may just set up a dog/child housing swap, pairing needy puppies with boys to wrestle, needy lap dogs with girls to chase around the yard. Everyone wins!
I'll take a small percentage of the monthly rent. Everyone wins!