What should a girl 5'2 weigh?

depends on how old you are of course!! i just turned 14 and the bmi calculator said 86-128 lb. and because your actually concerned as a teen, then i suggest you not borderline the 128, but lower than that.

go to the site here to calculate your own bmi: http://kidshealth.org/teen/food_fitness/dieting/bmi.html