Maybe the best thing is to let her know how you feel.
Confront her. Tell her what you think. And, not to make you feel bad or anything, but in 8th grade and through out Higschool, you'll deal with a lot of loses. Friends will go to different groups, they'll end up smoking, all that. It'll be hard, but if you have those real close friends, all will be good. <3 So tell her what she means to you, she migth understand. It's always worth a try. <3