As a girl who wasn't the “average” anything, I can relate to girls who are insecure about their size. When I was growing up - where I'm from, most girls were between the sizes 00 and 7, I was never even close to those standards. I always thought that this was a bad thing, that I was ugly due to my weight and lack of a flat stomach. That's always the stigma that comes towards girls who are a little chubby or overweight, that it means you are unattractive.
It has taken me years and years to finally come to terms with the way my body looks. I promise it comes in time, you just have to remember that you are there for you before anyone else. I feel like you have to look at yourself and think “do I like me” not “will they like me” that's how I found myself loving myself more. Do things that make you feel confident, things that make you smile and do those things with a disregard for what others have to say about it because if it makes you happy that is all that matters. Find clothes that make you feel amazing! For the girls that are maybe a bit overweight and don't quite fit into those Hollister and Urban outfitter sizes- try some cute stores that have really nice plus-sized clothing!
I also want to take a minute to talk about really accepting the fact that it's OK to shop in the plus-sized section. For the longest time I didn't want to shop in plus sized because it made me feel stupid that I was “fat” and thought I'd be ridiculed for it. But I soon realized that more and more stores are coming to accept women who are bigger than a size medium or large! Take Forever 21 for example, it is a store that is very famous and popular in society. They too have a plus sized section, and the clothes are still really nice! Don't be ashamed of shopping plus size because honestly who cares what the size is if you are comfortable and confident in it! I also realized that if someone is ridiculing you based on your clothing size or clothing choice they aren't really the type of person you need in your life.