Is 156 pounds overweight for a 14 year old girl?

It may or may not be. There is no specific weight for a 14-year-old girl because weight is related to height and body composition rather than age. Please feel free to ask the question again and include those details. Alternatively, for in-depth information about weight in relation to height, and to see charts showing the distribution of weights and heights of children at various ages, please see the page link, further down this page, listed under Related Questions.