A 14-year-old girl in the 50th percentile for her age group weighs about 109 lbs., as stated by the Centers for Disease Control. In other words, 50 percent of 14-year-old girls weigh up to 109 lbs.
The weight range for most teens this age is between 80.9 lbs. and 171 lbs., as stated by the Centers for Disease Control. Meanwhile, the average height for a 14-year-old girl is about 62.5 inches, as stated by Disabled World. At 109 lbs., this height is within a healthy body mass index range. A BMI calculator can be used to determine if the weight of the teenager in question is within healthy ranges.