Small women can birth large babies in many situations. My grandma did it. Same size as me, 4'11" in height (at most, that is) and she had a big baby or two. I think she had one in the 8-9 pound range. Pygmy women have 9 pounders all the time, from what I have heard. And they are just small all around. I think that would be like a large or average sized women birthing a 15 pound baby. I'd be tall in a pygmy clan, most likely.
Anyway, so here we have this great diversity of people. Some very big. One very tall mama/husband in the US (in the news cycle a while back) had a homebirth with a 13lb baby, yes, vaginally!
But back to the little people. Mind you, my husband is only 6 inches taller. Very well proportioned and attractive. So he's not giving the children much incentive to be big. And we were both smallish newborns. I was around 6 pounds, he, 7. My 6 children's weights were all below 7 pounds. Despite me resting, eating right and gaining on the plump side (especially last time) for good measure. I am a happy person but often sedentary. I am interested to know if sedentary people have smaller babies. And by sedentary I mean I do house chores, homeschool and nurse, as well as writing and researching online (sitting on a swopper chair, so sitting in motion). I stay put in the house alot chasing my ambitions here. I used to walk every day if I could but haven't done that in a while. I do bellydance and stretch a little bit and even cycle indoors while watching the kids as I've started to be active again after birthing the last baby who was 3.5 pounds.
You read that right - I said my last baby was 3.5 pounds. He was probably a twin or even a triplet (to explain his extra small size) and he was born early. But he thrived like a full term baby in every way. At 12 weeks he's 9.5lbs now. We did hear an extra heartbeat and I even suspected that there were three in there at one point, halfway through. Because up until 24 weeks I was growing at triple speed. They were too early to intervene on so I continued the UP route for Mike's sake and hoped for twins but the pregnancy went on beautifully with the survivor anyway. If it was a triplet/twin to singleton pregnancy, though, it was one where the entire lost part of the pregnancy was reabsorbed. I know it can be done in many mammals and even in the first trimester of human pregnancies. I did not know it could happen in the second. But who in the medical community would allow a chance for that? They would want to scrape it all out if it didn't all appear at the birth, because they would have been scanning and probing the entire time and having all these expectations of what to do.
Supposedly it is also not possible to birth a 36 week, 3.5lb "singleton" at home with good results. But I did.