My cousin copies everything I do!?

I'm 14 years old and she's 12 years old. Ever since we were little she copies everything I do! Like when I accidentally drop something I say "Fudge!" and ever since she heard me say that, she began to say it too. My mom and her mom (my aunt) are close so sometimes the 4 of us would go to the mall and buy clothes, then when I'll choose my own clothes to buy she's gonna look at them and then ask her mom to buy the same clothes that I chose but with her size! WTH?! And that's not all, SHE EVEN ADDS MY FRIENDS AND CLASSMATES ON FACEBOOK! She doesn't even know them. When I'm gonna log out on FaceBook, I always say "Out for now.", next thing I know she writes that too on her wall when she'll log-out! I also started putting random quotes on my wall and then she does that too! Talk about copycats! LIEFGQSHLKJFHLKLQ