If you set them together on point with the same size plain blocks inbetween it should be big enough for a quilt. I would machine quilt the plain blocks and then do all of them QAYG. By machine quilting the plain blocks it will really set off the hand quilting that her mother did. Don't get too fancy with your machine quilting, keep it plain and simple.
attatch then together the same way Ditter showed in her string quilt tutorial.