Kaffe Fasset has a lot of large scale prints that I think would appeal to young girls. But again with that many needed it will get expensive. Have you thought about using batiks? With the color variation in large scale on many batiks it would give you the look of different fabrics. I don't know what size the finished quilt will be but with the 30 FQs that's over 7 yards of fabric so unless it's going to be a very large quilt I would check the pattern to see how much of the FQ you actually use.