How to politely say no??

My bridesmaid (who by god I love to death, but doesn't have quite the same tastes as I do), just offered to make me either a bracelet or an anklet to wear on my wedding day. She said she doesn't want to tell me exactly what it would look like and she wants to keep it a surprise. Part of me just wants to tell her to make it an anklet so whatever it looks like no one will see it (which seems really mean?) But I really don't like anklets very much...



I want to be nice, and I don't want to seem like a bridezilla, but this is my wedding day and I really want to look exactly the way I envision. I really appreciate her offering, and I don't want to hurt her feelings... What should I say to her?