kaiti-
Welcome! I fully agree with Suzanne's advice, that rather than going on a diet and counting calories or every morsel that you eat-that you start with the small changes and see what happens over time. The key is for you to slowly develop healthier habits and become fitter and healthier over time.
I cannot stress how important it is to be active-to me, that is the first and foremost thing that you can start doing to be healthier. Being active can mean the things you are doing like dancing and going for walks-but it can also mean fun things like swimming with friends in the summer, and walking around the mall shopping.
A few rounds around the mall-and you have walked quite a bit.
If it is important to you, mention to your mother that you would like her to keep some healthy snacks around the house-baby carrots, grapes, bananas, etc. Foods that are healthy, and easy to eat as an afternoon snack or a quick breakfast. I rush around in the mornings as well, and while some fruits don't travel well, others do-it is really easy to grab a handful of grapes or something like that as you run out the door.
Basically I agree with trying to stay away from the junk food. If you go to the mall or to fast food places with friends, for instance, rather than getting a frozen sweet coffee type drink like I see a lot of teens ordering (basically a milkshake with a dash of coffee in it) they usually have the nice glass bottled natural sodas there-and usually have diet...or you could get a bottled water.
In fast food places-you can choose more wisely in just about any of them any more-a Fruit/Walnut salad or regular salad at McDonalds is much better than the burgers and fries. Every now and then I realize that you HAVE to have burgers and fries-so in that instance, I suggest (and I do this too!) getting the kid's meal-because the portion sizes are much smaller. It is better to eat a "little" junk food now and then rather than eating a huge portion.
If you have any other questions or concerns, or need help with anything at all-just let me know.