Ok well i have this same exact problem. this one kid i have none for years has these news friends but am friends with all of these kids but the other day i pick them up from school and bring them home tony goes on the net so then i wanted to go on the net and the kid i have known for years throws a hissy fit about me going on the net then tony goes on it again and he has no problem so i lefted.
but here is the thing. Ur friend likes thie "new toy" of hers she will hang out with her for a while and might treat you this way fora while. But she will soon relize that this girl isnt at all what u can be to her. she mightthink she is cool now but i bet that she will find something she doesnt like about her and relize she can not replace years of friendship over a new friend. Now since u are girls why dont you talk to her about this and tlel u how u feel. guys would never do this but by confronting her u might be able to find out the problem. but just wait a lil bit and let ur friend try to figrue out how important true friends are.
i hope this helps i am tired ill giv u a better idea tommarow if i come up with one