While we're not the biggest of families, we're still a family of 6.
My DH is the sole provider and brings home a decent income which makes it easier for me to be a SAHM.
It all comes down to budgeting correctly I guess. We pay 1/3 of DH's income on the house, and we run 2 cars. We buy all our food as cheaply as possible but are still able to afford some luxuries. I love to cook so that helps a lot. We try to save money each week but end up having to go into it for things like birthdays etc, but we kinda figure that's what the savings are there for.
We're lucky as our children are fairly spaced apart in age which for now makes things a little easier. DH & I always knew we'd like loads of babies but money is the only factor that really stops us from having more, I know for us another child would put us into a much dire predicament, which is why I am more than happy to stay a family of 6. If we happen to get an amazing lotto win, things may change