hello..
is your height is 5.1 or its 5.10 (6 feet)??
so if its 6 feet your weight must probably be between (135 to 165 lbs)
but if you are 5.1 feet your weight range should be between (95 to 116 lbs)
you can check your bmi (body mass index) to make sure if you are in the normal range -----> http://www.nhlbisupport.com/bmi/
hope that i helped you with my answer..