The quilt is so beautiful. I would continue hand quilting if it took until Easter. Your in-laws will appreciate the effort. While I love machine quilting, hand quilting is still my favorite. Also, combination quilting may or may not work very well. The machine stitching is tighter and the quilt will likely not wash satisfactorily. The center will always be softer.
Take a photo and wrap it up with a nice note of explanation. They'll still love it!