I used to be in your shoes, ladies. All of my life I was super thin & where it says "5'9 115 lbs" on my driver's license it was the truth. I even had a gym teacher call my parents & ask if I was ill. I complained about how people would say "you're too skinny" and never realized how dependent I was on hearing that.
When I started college I began extreme yo-yo dieting in reaction to the stress. Knowing what I know now, I probably had an eating disorder. I lost weight I didn't really have, then realized the problem & resumed my regular eating habbits. My body reacted by storing every calorie I ate in case I stopped eating again. Two year later I am an average weight, about 135 & still 5'9. I hate more than anything being a normal size. I used t complain about being the skinny girl, but I became dependent on that niche. I think it boils down to you're never happy with what you've got & you never realize what you had until it's gone. Twiggy girls- don't get traped in the skinny girl mentality, you'll wonder why you ever complained about it when/if you gain some weight. Sorry for the long post
Heidi