I'm about 5'3" and hover between 118 and 128. My mom was smaller than me when she was my age, and stayed pretty lean even after having both me and my sister, just gained a considerable amount of weight after she had a full mastectomy and reconstruction. We also moved.. she didn't make new friends, really. I'm afraid I'll fall into the same habits, but at the same time I really like to ride horses and I must stay in decent shape to do it. If I get too fat, my horse will definitely let me know.
(And I'm sure Crompsin will, too.)