That is stunning!! How did you add the border to the edges of the Ada fabric? I've done some great pieces, I'd love to incorporate them into a quilt.
I don't trim the Aida fabric. I draw a line a quarter inch from where I want the border to be. Lay the border fabric face down and sew my quarter inch seam. If I want mitered borders, I sew the border pieces together leaving a 1/4" unsewn on the inner seam. Then I press in under and machine applique the border on.
I have found that if I trim the Aida fabric, it tends to fray and pull out of the seam. I usually 2-4 inches of extra on each side. Once I quilt it, it won't pull out.
That is just beautiful! Wow, that's alot of work to donate for your siletn auction. There are a lot of hours put into counted cross stitch but the end result is just too cool.