I think i feel jealous...?

I dont know whats wrong with me. Basically its my cousins (from my mums side) wedding. She is planning on inviting one of my aunts from my dads side and my cousins. Im not arrogant or anything but at most wedding I tend to look very pretty, and the nicest. I get a lot of compliments. This cousin (Who doesnt live where i live) is EXTREMELY pretty, she is absoloutly gorgeous. She is invited to the wedding, and I dont know why but I feel a pang of jealousy that Im not gonna look the best. I love my cousin to bits, and I get on with her reallyy reallyy well, but I dont know why Im feeling like this, I dont think i want to go to the wedding...