Do you think I as in me, myself, and I, should lose weight?

Well, I'm either 5'0'' to 5'3". I know, I'm short. I'm also 105 lbs. But, I'm also from 11-15 (I'm not going to tell you!). I friends say I'm skinny, but I know I'm not. They say it's muscle (yeah, right!!!) But my BMI is normal. But all my friends and people are skinny. Not unhealthy, but I'm soooo jealous! Please tell me your opinion.