Annoying 4ss Cousin

Have ya'll ever had a cousin that study in the same class as you? That's happening to me and she is so annoying. Like, she is fake and envious and she always judge anything I do. 

She started to judge me since I won a drawing contest, in which I was the only one who really dedicated herself to it, because I love drawing. Since then, she has been a b1tch and annoying. And I can't even tell her mother, because, her mother is so nice and my cousin have good grades. Unfortunatelly, she will be in my class in 2025.