Nice. Is it enough drawer storage right at the vanity for the both of you?

No plans to fix the window?

@PPF. What do you mean? Fix what about the window?

This. It looks like an oops, or like the window should be moved or removed. If this were new construction, you would never see a window placed like this.

How long is the vanity you have planned? How many inches have you alloted for the toilet?

Answering your question about the pony wall. it give a small sense of privacy to the toilet. I feel that it looks a little tall in the diagram though. I do agree the window looks awkward, but so what? If you are good with it, we are!

The window looks like a mistake because the high cabinet is "notched" around it with a pretty unusable sliver of a counter. If the high cabinet wasn't there, and even the shower wall was glass, it wouldn't look compromised and the room would feel bigger too.

The pony wall does gove nice separation. And a place to set a phone or something off the counter, if it might otherwise get wet.

For the little nook, could the tall cabinet be shallow cabinets all the way across, above a standard or same-depth base?

I’d try a couple of versions before committing to this layout, especially since everything except the toilet can still move. The pony wall might feel quite different in the actual room than it does on the drawing.

You could quickly recreate the 9 × 10 space and compare a few options in 2D/3D here:

https://homdera.com/en/tools/home-planner

I’d also try one version without the tall cabinet by the window — it might make that side of the room feel noticeably more open.

Our bathroom has a pony wall, then it steps back to a full-height wall. Nice separation, and allows for a medicine cabinet on the vanity side.

Thank you all so much for the comments and suggestions - super helpful! I'm thinking I will get rid of the upper cabinets and just have the lower ones, and see if I can have just a glass panel for that side of the shower. It seems like if I do this, maybe it'd also look better to get rid of the pony wall next to the toilet as that might look out of place with the other barrier gone (between shower and cabinets). Agree?

The pony wall is a nice finish to the end of the vanity. You know how exposed the toilet feels-does the pony wall solve a problem?

Really, the window is key here. It appears the line in the drawing between windows could have been a wall you are taking out, so the first thing I would ask is are the windows the exact same, or different sizes and styles. Same = keep can be ok, different = remove one, or redo into a single larger or mulled or etc.

Usually, dimensions on a 2D floor plan and more info is given for pertinent advice. I will assume it is a 72" vanity and 32" toilet space, which makes the shower look like 60" including a bench. In general a shower should be a bit larger when having a built-in bench.

I'd look into moving the toilet to next to the shower. Without dimensions, it is hard to tell if another layout may also work.

With the toilet moved, you can do a pony wall next to the shower , which will allow light into the shower.

With a longer vanity, you can do more drawers.