Make something that you know she will love.
If she was a flower person ... then something of that sort.
Or did she love cats? dogs?
Was she a quilter? what was her favourite quilt pattern? Then choose it.
Likewise pick colours that are hers!!
Ideally bright and perky, so she can see them from afar.
While the door is open a lot, putting it on the wall,
might be closer and easier for her to see and enjoy, than on the door.