...My friend copies my style...?

I'm not trying to be horrible... But you know its fine if you have the same tastes... but for example.. I dress differently and she is barbie... and she likes things depending on whose in the room... But now she got black skinnies when I got a pair... As well as high tops after I got them... She listens to Cascada and britney spears, etc.. I listen to dragonforce, haste the day, system of a down, etc.. But now she loves my music.. I do piano, Guitar and drums now she is starting piano and guitar.. I have to wears a ankle and knee guard for sports now she wears one too after not using one the previous practise... Im not trying to be horrible at all but do you think she is copying me?? If so... How do I tell her to stick to her style without coming on too harshly... shes the type of person who sometimes tells her mom, etc whose being mean to her and stuff but i don't want to get into the bad books... Just want her to stick to her own stuff...