I'd switch the toilet and the vanity because I'd rather see the vanity through the open door than a toilet. If the toilet moves next to shower, you could put a luggage rack type shelf above it for towels. You could make the window narrower to accommodate the vanity in that space.

Thanks for the comment! I cannot change the size of the window as I am fitting the bathroom into my existing space in a 1905 rowhouse.

You might be best to use the plan as drawn. If you move the toilet to where you have the vanity drawn, you may have trouble fitting in a shower glass door that can open, unless you are using a shower curtain. The 30 inch depth toilet would block the shower door.

If you do want the toilet on that wall, you would have to do a wall toilet that is only 24 inches deep compared to a standard toilet that is about 30 inches deep.

Using your drawing, I'd make the shower about 34 inches deep by 46 inches long and the vanity about 32 inches long so that you can do a pony wall between the shower and vanity. If you put your shower controls on that pony wall, it will be easier to turn on and adjust the water temp before you get in. I'd want my toilet space next to the shower to be at lest 33 to 34 inches wide.

Since your bathroom is small, I's put a couple of towel hooks on the back of the door. I always take my towel from the hook and place it closer to the shower before I get in.

That's interesting about relocating the shower controls. Thanks for that feedback, I'll talk to my contractor about it.