I agree w/ much of what has been said, but I do prefer a bit more on the sides - about 5 or 6 inches so that i can keep the top anchored in the frame (I hand quilt). If someone else will finish this for her - let them guide you on the batting. Personally, I like 100% cotton batting and would rather not quilt w/ the polyester battings. I do not like the way they come out - esp for something like you have, it deserves to have the best that you can afford.
I feel the same way about the thread that I use...Hmmmm...I guess i'm a thread and cotton batting snob!!