SuzzyQ

I'm making a quilt for my 9 year old GS and I'm stuck. It will be similar to the one I made for his cousin (picture attached) but there are six larger blocks (20") that the smaller bits will be filling in around. I've had him put some smaller squares with each large block but ... it's given me a start but I'm still struggling. I'd like to keep the big blocks on top of the bed (double) so just concentrating on a space 60" x 72" for now. Second picture is what I'm working with.
Grandson really liked working with the quilt squares!