BNB - I actually have to think about that for a second. I know at one time (last summer) “Becky” and her kids were here for the day swimming. I forgot to mention that she also babysits for a couple kids, believe it or not. So let me think… her six, plus the little group of three sibs she had, and two of her babysitting kids… I think that was her max to date. So actually living in her house at the time were nine. Occasionally, she ends up with an emergency care kid - a young teen tossed out of his home in the middle of the night, or a group of sibs that was in immediate danger and needed beds NOW. Somehow she manages.
I sort of see your point about fostering “extras” as opposed to birthing them, but kids are kids no matter who brought them into the world. I would gently suggest that it’s more a case of what we’re used to than anything else. Most of us would be completely overwhelmed at the idea of more than two or three kids, so naturally we’d look at someone with 14 and think, “holy cow!”
My own childhood as the eldest of a huge brood is atypical at best. As I said, lots of step and half sibs, which means there were multiple marriages and such, plus even without ANY kids my parents would have been classified as dysfunctional in the extreme. I’d feel funny about posting my experiences only because they’re so far off the map of normal that they wouldn’t even compute.