There may be several ways but how I'd do it is: You would sandwich your three layers like a regular straight sided quilt (backing, batting, and front), then baste and quilt. After quilting it you would trim the batting and backing even with the front, then put the binding on as usual. It would be important that the binding be bias (cut on the bias, not on the straight of the fabric) so it will have enough 'give' to go around all the angles smoothly. Alternatively, you can add the half-hexies to make it straight sided so it wouldn't be necessary to use bias binding, but either way would be nice, and make a nice gift for your MIL. I didn't check, but there are probably loads of tutorials on the internet for this if you want to google it. Good luck! And please post the finished table runner so we can all see it!