There are the wall hangings that it looks like one block has jumped out and is hanging there. Can you use that idea to leave a hole? Or when putting the binding on, leave a space with maybe an extra couple inches of the binding hanging loose, creating a "hole".

Depending on the size, could you add it to a label that you put on the back of the quilt?

I would put it on the back as part of the label.

Use several layers of dissolvable embroidery stabilizer instead of interfacing and it will wash away. Create the hole the size you want and zigzag around it at moderate width and very closely like you would for appliqué, letting needle be just off edge of fabric.

What about constructing the quilt with the quilt as you go method? Then one of the blocks will contain the hole. I'm thinking a block would be easier to manage to do a facing method, buttonhole, or whatever. Its also a way of developing the idea without wrecking a whole quilt, just try making another block until you get the one that works.

If you can get the actual thumb hole area and attach it to a similarly-colored background piece (or even a piece of another similar-looking fabric, loosely woven), then you might be able to overlay it with a piece of white/neutral-color tulle and carefully stitch all of it in place with clear thread.

Of course, you might want to try this a time or two with other-than-precious fabric, cut away a bit of a small hole and work at fraying the hole edges before putting it between a foundation piece and tulle.

The tulle and clear thread will practically disappear when done, but it will hold everything in place, especially if the piece ever gets carefully washed.

Just a thought. Keep us all posted on how this precious project ends up.

You've got some good ideas for the hold. I'm thinking you might want to put a little pocket on the front of the quilt and then put a little piece of the baby blanket in the pocket. (Depending on the size of the baby blanket....maybe put the whole thing in there).......or on the back?

I knew that I could count on all of you to give me some great ideas. I was completely stuck. I don't think she can part with the baby blanket which is too bad because a part of it could be better preserved with some of these ideas.
She really had no requests for the t - shirts, I had her number their order of importance.
But about this she was definite, Top left hand corner as you look at the quilt. So I know that this is very important to her and it kind of freaks me out. I hope I can do a good job. I have made a lot of quilts but they were always what I wanted. The only other quilt that I made for someone specifically upon request was for a 10 year cancer survivor. It was a Dresden plate quilt using her chemo scarves. It was a request from an employee who know I quilted. It was the most rewarding quilt I have ever made. Maybe I can do this.

glad you got some good ideas. please post a pic when you have it finished.

Well, since the little guy made the hole.... I would make and complete the quilt. Then take a dremel to the corner that you want it will drill a hole, a small one with ragged edges. If you used the warm and natural batting it won't fray and should hold up to many washings.