The first step is for your friend and her husband to decide how much they can/or are willing to spend to finish the quilt tops they have. To make a quilt top into a quilt you need backing material a number inches bigger on all sides than the top, batting material same size as the backing and material to make a binding.
As your friend isn't a quilter she would have to hire someone to finish the quilts. If the grandmother hand pieced(sewed) the top together they might want to have the quilt finished in the traditional manner. That is, the quilter would make a backing big enough, then layer the backing, batting and top on a large, hard surface. Once layered, she would then put safety pins every 3-4 inches through the layers to secure them. Once, secured the quilter would then hand quilt the quilt(sew through all 3 layers). There several ways to hand quilt, including using a hoop or quilt stand. After quilting the entire quilt the quilter would then make a binding and sew it to the quilt edges to finish them off. As you can see, this is a very labor intensive project. To hire someone to do this would be quite expensive but perhaps desirable if they want a traditional, heirloom look to the quilts.
Regardless of whether the quilt top is hand sewn or machine sewn they can decide to have the tops finished using machine methods that are faster and less expensive. They can also decide to use polester batting which is less expensive than the more traditional cotton batting. They can find a longarm quilter("longarm" refers to the large sewing maching used) through a locoal quilt store or through the internet. Most longarm quilters, in addition to layering and quilting the quilts quite quickly, can piece a backing, supply batting and make and apply binding. Though a very new method, binding can be applied entirely by machine, another money saver. This second method is less expensive than the entirely hand method.
So it all depends on what finished product would satisfy your firend and her husband and their budget. If they can go to a quilt show they could compare the differences between the two methods.
Good luck to them in getting their grandmother's work finished.