I made a similar lap quilt once. It was fun, but I'm not sure it goes by her specifications. It was six lines of color that made each block and you made 4 of those. 2 tone on tone prints of each rainbow color in each line. Kinda like this
Aa-purple
Bb-blue
Cc-green
Dd-Red
Ee-Orange
Ff-Yellow
Each block could look like this (Only one strip per line of each color, I just use the letters to show length of strip)
AAAAAAAAAaaa
BBBBBBBbbbbb
CCCCCccccccc
DDDdddddddd
EEeeeeeeeeee
Ffffffffffffffffffff
Then you turn them in different ways once all four are finished and it gives you a rainbow effect with no partial circle seams. Not sure if it's what you are looking for, but it was the first thing that came to mind.
Melissa