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.