I'm a 21 year old at pretty much the exact same height and weight you are
As teenage girls are still going through brain, bone, and sexual development (even if you think you're done growing), they need a lot more calories than you'd expect. For your height and weight your caloric intake should be around 1800 calories a day, so a day of around 1300 calories is definitely not overeating.
My mom was and is the same way about my eating habits. She'd always chime in with things like "are you sure you're hungry?", "didn't you just eat?", and "don't eat just because you're bored", which can be hard to hear.
I'm assuming you're quite healthy so if taking in an extra 500 calories a day seems overwhelming, just ignore calories and eat what feels right. Our bodies are very smart and if we listened to them more often we'd be just fine
Hope this helps! If you have any other questions I'm here to listen and offer any advice I can.