Are you the same Anonymous questioner that took a pill and gained weight and then wanted to know why your mom waited to take you to the doctor's office?
If you are a teenager, you will have some weight gain due to body changes and the onset of puberty.
However, you need to take some personal responsibility here. Just because you are given unhealthy snacks doesn't mean that you need to eat them. Your mother is trying to keep you healthy so you don't have an extra 50 to 60 pounds that you are carrying around.
Stop blaming the neighbor for giving you "big meals and snacks". You're the one putting them in your mouth. You have the ability to say, "Thank you for offering me a snack, Mrs. Hansen, but I am trying to cut back and lose a bit of weight before school starts up again."
If you don't developed some self-control, you're going to have bigger issues than your weight as you get older. So thank your mother for caring and learn how to say NO to your neighbor.