Is 115 pounds normal for a 5 foot 1 inch 14 year old?

Can be normal. General guidelines for average BMI call for 100 lbs for the first 5 feet and then about 5 lbs per inch. So your weight is close to that. Another thing to consider is how has your weight changed recently. Have you lost or gained a lot of weight? Try to keep the weight constant, at this age for a female you are mostly done growing.