Looks cute. You could install a prefab. There are some newer nicer ones. You are going to lose that window if you do the shower you'll need a much higher and shorter one. And whatever that cabinet is will have to go too. If you have a lot of places to spend money, maybe start elsewhere. Its looks nice and clean for now.

I would Just add a glass plate as seperater, and add a new zink and toilet. some bigger tile would also look great.

I appreciate the input. Thank you!
So, we would definitely have to lose the window if we do a tile shower? I really like windows and hate to lose it.
The tub needs to go. It's rusty and gross and doesn't drain well. No one will use it.

We demolished tub and made shower

Thank you all for the great ideas!!! This is the first time I have used this feature. I may become an addict!

You could put a rain shower head mounted in the center. If you do, consider replacing the window with a non-operable one or gkass blocks...water is your house's worse enemy...no reason to tepmt fate, get it sealed tight. I don't know how to remove my photo, so I'll just say we added a window and extended rhe window sill across the shower for a shelf. but our showerhead is far from our window and high so angles diwn.

Good luck with your project. Keep us posted with your progress!

I thought the window was wood casement. I thought that was the reason there wasn't a shower there already. Is it wood or vinyl? Glass blocks would work probably, but it would still be better to put a high slider window you can open. Otherwise you will need a good vent. Sealed bathrooms grow mold. Are you planning to reconfigure the pieces or just upgrade? It doesn't look like you have room for a shower on the side wall. What size is the room? Do you want a vanity too?

I change my recommendation. I thought the arch was cute so suggested a center mount, but it is so easy to remove the sheetrock and get rid of the angle....and you could keep the facade of the arch facing the room but remove the slanted wall in the shower. You have to do drywall work anyway...actually, not drywall, use the denshield which is resin impregnated, fiberglass coated gypsum in the shower under your tile. You want your bathroom to be standard, Change out your shower valve while you have the plumber there and get a single handle valve...maybe one with separate temp and volume adjustments (mine is not, just lower end Delta and I like it fine). Your tile is so adorable. I wonder if you coukd salvage enough in the tear out to use it in a listel or border when you tile the new shower ...to tie the shower to the existing tile wainscoting. You could use oversized white subway tile with a yellow border, maybe with a black pencil band on either side of the border.

You need to discover why the old tub drains poorly. A shower might have the same problem unless you replace the drain, pipes, or whatever is causing the trouble.

If you have no other shower in the house and want a fast temporary fix you have an access panel in front....add a shower as high as you can....and go to home depot and get a danco showerhead extender that allows you to raise your showerhead a foot. Use white melamine craft panels to waterproof the walls above the tile...like wallpaper but a bead of sealant on seams. (Sealant v v important) Mini shower curtain over access door.

While at home depot get something to stick down your drain to get the hair out...

Slant in the ceiling is no problem get glass shower that has built in bench where the slant is. If you really want to go all out, on the 2nd pic of the white shower see where the shower head is its right on the top of the ceiling another way to use your space wisely. Hope it works out!

Love the ideas and suggestions, everyone. Thank you all.
Yes, plumbing is probably going to have to be replaced. This is an old house.
The window is vinyl, but has wood trim. Could be trimmed out with tile though. It is a "crank out" window. I think is should be salvageable, but my husband isn't so hopeful.
The arches can't be straightened as there is roof above. We will definitely put a vent in. I like the idea of having the shower head in the middle at the top.
I appreciate that someone sees value in the tile. I don't love it, but really like the idea of salvaging some of it to use as an accent.
Thank you all again for taking the time to help out. I really, really appreciate it!

Question? Is this an attic shower? Meaning are the two slopes the roofline?

If so, will you have another access to plumbing fixtures in the future? Not sure what part of the world you live in but if it ever freezes where you live you need to consider losing access to your pipes.

If you consider a rainshower, remember you're not gonna have much room up there if that is the peak of your roof just above your ceiling.

Good point!! It's not an attic, but it is the upstairs and the bath is in the corner. It's the little window at the top.

Not an attic but the same limitations for space. Do you live in a cold climate?

Yes, in Missouri. 100F in the summer, -0F in the winter.