First, go to your local thrift shop and buy a couple of old suits to play with. What I would do is cut the suit up the sides and remove the back. Then cut across the suit at the waist. measure them all and get the dimensions of the largest one and cut all your squares that size (I'd use some 'water' colored batik, or light blue). Then I'd machine applique the tops (bodice?) of the suit on to each block. I'd probably try and get away with no interfacing, but you may need to fuse the suit to the backing. You could try and just use a heart shaped piece of fusable. Need to use a press cloth to make sure that you don't melt the suit. You could practice on the discarded backs. You could quilt a simple heart on each bodice, and do waves on the background fabric.