How do I tell my couisn to stop copying me?

MY cousin Mercedes is my bestfriend but she copies off me. I stared doing this signature think Raveen Payne the official. XX then she started doing it. I started saying Arr then she started saying it. I started dying my hair then she did it. SHE said she hated the wanted! I told her I liked them then what do you know she likes them the next day. She just won't stop copying me and it pisses me off but I wanna tell her to stop but I don't wanna make her mad.

sit her down and have a chat....if she is your best friend,she would really appreciate it coming from you than any other third person.