Hey there! I know what it's like with the older, beautiful, skinny sister. I have two...the oldest one has to work to keep thin, but the other one has to eat, eat, eat, and eat some more just to keep from being underweight (which I think she is, anyways). I'm, of course, the tubby baby sister. They can both wear size 6's and I...well, I'll never be able to wear a size six, just because of my body frame and bone size.
Congrats on the 18 pounds you've lost! That's absolutely terrific!