Do think 115 is an ok weight for a 15 year old girl?

The weight of a person depends on their age, height, gender, and overall body composition. Therefore it is not possible to determine if a weight is healthy or appropriate based on age alone. It's important to consider overall health and the individual's unique circumstances. If you are concerned about your weight or that of someone else, it's best to consult a healthcare professional who can provide personalized guidance and support.