Im really jelous of this girl,,,?

ok there's this girl called Jessica and she's only 16 but she's started hanging around with my group.. and its not that i dont like her, i just hate her and i hate to admit it but im so jelous of her! its always been my little group with the boys and 2 of my closest girl friends.. there not really around as much so there not ut as much so its just me with the guys and tbh im only there cos my brother is... anyway this girl has suddenly started hanging with them! if i ever walk up she's there with all of them! even when she's not there all they say is 'wheres Jess' or talk about her 24/7. she had something going on with one of them but it went all pear shapped and then had something going on with the one i like! and they all dote on her, they always are around her and listen to every word she says its a joke! i'll admit she is very pretty and the thing is she's not a slag but she is... like she doesnt have sex with loads of guys shes just a big flirt but she'll only do stuff with the guy she's going outwith after 3 months.. so i dunno why all the boys are in love with her cos its not like shes easy.. i dont know how to get rid of her..