Friendship...it matters part 1

Hello dear friends, this is basically a story rather than a quiz. But you will find one or two questions in the middle for you to think and answer. This is actually my first post in this site. Hope it is well.

So, there is a 13 years old fun-loving, cheerful girl with a smile on her lips, almost always. She is studying in 7th grade. But after that new girl appears, she and her life changes. What happens?? Go on and read if you want to know, and answer.