I love your choices, and second the idea of adding some black trim in the white. I think that it would be amazing. Are you thinking of crackle tile in the shower? If so, double-check if that is ok. I a have crackle finish backsplash in my kitchen and the manufacturer recommended sealing the tile to prevent any stains from food splashes seeping in through the cracks. That makes me think that it might not be a great option for a wet installation like a shower. Hopefully someone more knowledgeable than I am can chime in.

I have a small house. Small baths. You don't like housecleaning nor wiping down after kids. One thing I did was I got rid of the ceramic tile tub surround and had white swanstone panels installed. I never want to clean mildewed grout again. I love tile and put it above the panels. Yes, I prefer, way prefer the look of tile but not at the cost of cleaning it. The swanstone looks pretty good. Sorry no pics. I have two Americast tubs and I think they are acrylic..I love them. Had cast iron before. They are shiny, sparkly, fresh and white. I think my cleaners use a spray to clean them. I am glad you are thinking this thru before you do extreme drastic measures. 1000s f is not going to be better with the addition of windows. Editing, building up, and up going storage will help, not windows. Natural light is overrated. Look at small space solutions and not at glam or cliched luxury sites. We built closets onto our bedroom walls instead of new dressers. Up to the ceiling. Think California closets. With drawers and cabinets. Not pretty but functional. We have ikea Brimnes headboards with under bed storage drawers in our new house. I am an ikea slave. Your family is always going to take a lot of time and energy and that's just the way it is. A 1000sf house will not be easy but it's home. And I love love your kitchen. Think about the life you live for now. Think first before acting.

Could you please post a picture and some room dimensions? I don't know the dimensions of a small powderroom. We have a small bathroom as well. It is 'so small' that I leave the door open when others are not around, since the toilet seat used to rub on the door, but we got a different seat. Very tight space. We also remodeled it. Put in a Whirlpool tub (American Standard) that fit into a 60" space (our wall studs without any covering.) We also shoehorned in a 1 person Vanity. We found a vanity which we liked, with a drawer down toward the floor and stuff - but it wouldn't fit because of our plumbing. They didn't make a reverse or opposite. With some effort we took it apart and rebuilt it the way we needed it - so it would fit into our plumbing... It is now a very nice, and VERY small bathroom. It is also the only one my wife had growing up (she grew up in this house) - and was used by 5 people as well. With drywall, etc. our bath is 4'11" wide *except for toilet area which is less (4' 9.5" wide) & the total length is: 7' 11" deep. I have seen smaller bathrooms. But if you would give some dimensions... I am really surpised that we managed to shoe horn in the nice tub.

In your case, I would look to something like Barker Cabinets for an RTA cabinet that can be made to the exact specifications you need. I put one together in this link that is 28" (1" filler on each side) by 16" deep. You can buy paint grade or wood. You can choose your door style and have pull out shelves added if you like. You can also customize the height if you want to do a vessel sink. You can order them raw, or painted or stained. I think it's the best options to be able have a semi-custom size to suit your needs. https://www.barkercabinets.com/2-door-SINK-base-cabinet-p/b2dsink.htm