What is the average weight for a 22 year old female who's height is 5'1"?

100-132 pounds. Body mass index for normal-weight individuals is 18.5–24.9 kg/m^2. Given your height, your ideal body weight should be 100-132 pounds. See your physician to discuss any weight modification plan. http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmi_tbl.htm.