My daughter, who is also a teenager, has gotten a really small waist eating low carb. Hormones and food still affect her size due to occasional bloating, and that’s only natural. She eats as much as she wants, and doesn’t waste energy tracking. You probably have a good metabolic health, and can allow yourself to experiment with different amounts of protein and fat, as well as adding in healthy carbs like berries.
It is very important to eat enough. If you cut calories at you size, you are less likely to lose fat, and overeating (still low carb) once evry few days could make you see faster changes.
I get the impreaaion from what you are writing, that your waist has gotten smaller. If this ia the case, you should start tracking measurements instead of weight. The scale does not know the difference between strong and weak bones, good muscles and bad fat. A measure tape will tell you where you lose fat, and when you reach a healthy figure. It’s mostly about the waist/hip and waist/height ratios.