How long to you expect your kids to remain kids?

Creating permanent structural changes in a bath to accommodate temporary requirements is against common sense.

Design a bath that can be temporarily adopted to use by children but can convert back to a normal bath when the temporary requirement is gone.

Add more context.

A tub with shower will fill need as kids needs over long term. Invest in pocket door to have more floor space without the door swing. If you can manage a two sink vanity that will help.

If the kids are old enough to shower, you may not need a tub. That said, for resale value you need to have a least one bathtub in the house. You said “sink” - singular. If plural kids, you should try to fit a double sink vanity. Is this an existing bathroom to be renovated? If so, moving plumbing around can get expensive, and a pocket door may not be doable.

.

6x10 is a comfortable but not luxurious size for a bathroom. 5' wide is standard width for a 3-piece bathroom, so space is not an issue.

The obvious choices:

- How wide is the door? If it's an old house with a narrow door, replace it with a 32" door -- at some point you'll need to replace the vanity or the toilet, and you'll be glad to have a modern-sized door.

- Keep all the water works in the left-side wall. This is economical and limits potential leaks to that wall.

- Place a stand-up shower OR a shower-over-tub behind the door. Go with 60" wide x 30-36" deep. Definitely choose a hand-held shower head, which will be useful for washing the tub /shower.

- Towel bars reachable from the shower will be an issue here -- I'd put them on the back of the door, though that isn't ideal.

- That'll leave you 12" at the foot of the shower. Make that into a stack of narrow shelves -- image follows. That width is just right for stacks of towels, and you can add baskets to hide extra toiletries or extra toilet paper. Leave the bottom portion open for a narrow hamper. With no linen closet, you'll appreciate this.

- This leaves you space for a 48-54" vanity -- definitely not wide enough for duplicate sinks (but don't worry, as they're not useful anyway). If you center the sink, you'll have a bank of about 24-30" drawers on each side of the sink, which is very nice storage.

- That leaves the toilet over by the window -- 30" is enough, but 36" will be more comfortable as the kids grow /for adults that might occasionally use this bathroom. Don't build to minimum code -- yes, it'll pass, but you want comfortable.

• A tub with shower will fill need as kids needs over long term. Invest in pocket door to have more floor space without the door swing. If you can manage a two sink vanity that will help.
• If the kids are old enough to shower, you may not need a tub. That said, for resale value you need to have a least one bathtub in the house. You said “sink” - singular. If plural kids, you should try to fit a double sink vanity. Is this an existing bathroom to be renovated? If so, moving plumbing around can get expensive, and a pocket door may not be doable.

In what world do you think this slightly-wide bathroom cannot manage the door swing, but you can squeeze duplicate sinks into a 4' vanity?

Pocket doors are not desireable in bathrooms, as they will break (especially with chidren using them), and then you may need a professional fix. They're also more difficult for elderly people with arthritic hands.

Kids never use duplicate sinks anyway, and duplicates steal the counterspace, leaving no space for curling irons or electric razors -- or even tooth brush stands. Duplicate sinks are not a positive, and -- in this layout -- they're not even possible.

Got news for you - double sinks are great for a (multiple) kids bathroom if you can fit.
They can brush their teeth at the same time, and if girls, as teens they can both get ready in the morning at the same time