Hi. Can you move any/all the plumbing and closet around? How big is the shower in the drawing( drawing make it look a bit small)? And do you have any pictures of the current room? Would love to know more about the windows.

Please add more dimensions so we can help. (Size of linen closet, exact measurement/placement of toilet, width of entry door. Thank you.

Given the information provided I would extend the shower along the right hand wall, move the toilet to next to the shower (next to the window). Vanities along opposite wall. It's a shame to have to move the toilet, but it's hard to work with it where it is. At least you already have plumbing on both walls - you could make this work.

What is the elevation of the windows? (Distance from floor to bottom of the window sill?)

Without knowing the size, shape and placement of the windows, it's hard to say, but it makes the most sense to move the vanity to the window wall. Here are some ideas for placing mirrors when there are windows.

I'd move the door to the shower to the other side and put a slider on the linen cabinet to keep from having a 3 door jam where you do now.

Move the toilet to where your current shower stands so you don't see it from the doorway, Looks like you may have room for a toilet room as well. Flip the double vanity to the opposite wall where your currently resides as it's to have natural light for the vanity. Then extend shower from right window wall down where your double sink vanity is which would allow for a very large shower with a seat. The window maybe incorporated in shower but this all depends on your view outside, and your actual window locations, heights, and whether you decide you can move your toilet flange or not. You should be able to keep your linen? closet in the same location.