Friend who just made Facebook & is adding all Of Your Friends,& commenting on therpics Wen They Don't kno her!?

I have a friend that is a yr younger than me, I'm 15. And she, not to sound or b mean, has way fewer friends than I do. She's adding a ton of ppl she doesnt know& writing ily?&stuff. They'll write in her wall and b like do I kno you? And she says oh I'm friends with Anika. OMG. What do I Do to make her stoppppp!!!!?