How much should a 5'6 teen weigh?

The average 5'6 girl should weigh around 135-150 lbs.

Everyone grows at a different time, if you weigh less, you'll grow eventually. If you weigh more, you should probably grow more. If you weigh less and don't exercise, stop being bulimic. If you weigh more and don't exercise well then, exercise more.

Again, humans develop so don't be too hard on yourself if you aren't in the average factor.