My 2 sows are both around that size. I think they are on the large side of average. I think a lot of it has to do with bone structure... one of my previous pigs was just tiny. She was always on the low end of normal for weight (never even hit two pounds.) But she had a tiny face, tiny paws... just a very petite girl. Whereas Linney, my biggest sow, has huge paws, a big broad head, a big broad nose, huge eyes, etc. She just seems to be build bigger. It makes sense that that's why the range of normal is so wide- to accomodate some girls who are petite and some who are big boned!