How do I get rid of this phyco girl?!?

Okayyy so there is me, and my best friend well call her Taylor and my other best friend well call Emily and a phyco chick that is emily's enemy well call her Abi. So now that you know everyone; as crazy as this seems abi won't leave us all alone, she follows us around whenever she gets the chance but is always making digs(rude comments bossing us around because she's a year older) at Emily. This girl is crazy and the adults at our school always take her side! So Emily is just about ready to move schools and I really don't want her to! How can I get abi to leave us Alone (withOUT confrontation) so Emily won't leave our school?!