I think you could do what Patti Bee did, and line up the marble tile to match the height of the tile under the window. This will give you more decorating options for that wall. You won't be limited to a small picture that has to hang up above the marble. If you extend the backsplash out, it may beg the question 'why didn't you make the cabinet wider?' If you have a shorter backsplash, it will look intentional.

Since it's not an area where you're cooking or washing, it's really not necessary to have a backsplash at all. And because of the location of the switch plate, I'd probably choose not to do a backsplash. If you want a 4" backsplash, I'd stop it wherever the countertop ends. Here's a photo from the KitchenBlog showing an area similar to yours and you'll see they didn't do a backsplash. The blog has hundreds of pics so maybe you'll find more visuals that will help in your decision. Here is a link that might be useful: Kitchen blog

I have another question about this hard area to tile please. I will need to use a Carrara pencil edge tile down the right hand side (trash can side of wall) because the tile end is not finished. Should I also put the pencil edge on the left side too so that it looks symmetrical? When using a pencil edge, do you need to use it on all sides like a picture frame? Thank you!

Wow! So many helpful responses. Thank you! kim k, this picture is fantastic - just what I need to help me visualize what I am doing. By going with the 6" cab to the left of the DW, I can have a 3" filler between it and the corner, leaving 1 1/2" between the counter and the slider trim. The upper and lower cabs and the backsplash would then be 2 1/2" from the trim. Not as much as you picture here, but still some breathing room. If it turns out (as my KD is suggesting) that I don't really need a full 3" filler for the corner, then we can adjust on site and gain even a little more room next to the trim. herbflavor wrote: "I would avoid the area between window and door.....keep that area looking good,'" and "a deeper wall cabinet somewhere, with microwave on the bottom ledge of the cabinet is better than the protruding shelf only.......get the most flush look you can." What do you think of me changing the pantry cabinet in far right corner so the top is 18" deep (not 12" as shown) has only one shelf, and then putting a microwave on that shelf?