toverly, Bonnie specified in clue 1 that she was not using her special fabric for that clue, but just various of her navy fabrics.
Regarding the special fabric, Bonnie shows her piece early on in the intro. She said it was about 1/2 yd. It looked to me like a piece of navy heavily overlaid with white lace or embroidery. I think we will have to see how she uses hers in order to choose, but she also said a special fabric isn't needed.