My friend has been acting really weird recently?

She's been really withdrawn. She never comes out anymore, she just stays in her room listening to My Chemical Romance and going on tumblr. In cl, she never jokes on with us anymore, she just sits quietly there. Today I found her in the library, I asked whats wrong, and she just said "People. Can't stand them." I was a bit shocked. I asked her who she actually liked, and she said,"Jess, Alex and you. Thats it." She used to love everyone one! Whats the matter with her!? How do I get her to come round? Were in 8th grade btw. Thanks!