What a great Christmas gift!!
I would make the kit with lots of different fabrics rather than a few. This allows your GD to mix and match and create an unique quilt, ideally with no two blocks the same. I would choose either:
- Pre-cuts - There are many great patterns to choose from. You can also make your own pre-cuts from your stash.
- Quirky or Fun - Think cat or dog blocks where each block is done in Black on White or White on Black with a constant background and maybe the same collars. Two pattern designers that I really like are: sewfreshquilts.blogspot.com or madebymarney.com (I'm not affiliated with either but would love to meet them).