In my circle of friends, 2-3 is very common, but I do know a handful of families with 4-6. The only ones I know with more than that are in our homeschooling group.
In my husband's family, it is an unspoken rule that if you have a pigeon pair, you stop and if you get two of the same gender, you can try once more, but everyone stops at 3 no matter what.
We have 2 now and want at least 4. I am willing to go on having kids until my body is unable to anymore, but since we like to have three years between them, that limits us to 6 or 7 unless we have multiples.

