I also agree with contacting the person or organization about the size.
As far at the handwarming pocket, I would use fleece as it's warm and will not fray. You could attach it to any quilt pattern. This is how I would do it (assuming that it is a lap quilt and the top edge will be at the user's waist). Place pocket fabric on quilt right sides together. Sew the bottom of the pocket, reinforcing the ends. Flip the pocket up, then just catch it in the quilt binding.
[ATTACH=CONFIG]552688[/ATTACH]