I couldn't do exactly the same as the quilt, as I'd somehow pieced these differently. To overcome the problem, I've inserted a strip down the middle. This is from a piece leftover from binding the main quilt.
For the backing, I've used a shirt front in a pale lilac that compliments the pinks in the front. As it's not a square, I've made a cushion pad to go with it. It is the perfect companion to the quilt.