Of course, you can always do the quilt that alternates your focus squares with a four patch; in that case it's easy to alter the four patch to finish at the size of your focus squares.
Warm Wishes uses good-sized squares; you can always alter the block with the three strips to the 4.5 inches you want your focus square to be.
Although it uses 5 inch block centers, I think Stars of Hope on the Robert Kaufman site is a darling quilt if you don't have too many focus squares:
http://www.robertkaufman.com/quiltin...stars_of_hope/