Are there individual differences in how big the bellies get?

@Zeri I was just referring to the belly getting bigger during pregnancy, not weight gain after pregnancy. Sorry if I didn't word it clearly.

It may be because my sim started out on the thin side, but I've noticed it is pretty easy to keep her from gaining baby weight. I just send her for a long workout on the treadmill after every few kids or so, and she is still slim (it just looks like her hips are wider than they used to be, but I guess that happens in real life after having babies too so I am okay with that).