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It seems okay, but I'd advise a swinging door rather than pocket. Kids can have trouble with pocket doors. If you stick with the pocket, be sure there is added extra wall thickness as needed to be able to use the vanity sidewall for towel ring, outlets, light switches, etc.

I'd probably do something different with all that space, though. A shower-tub combo would allow room to separate the toilet and shower from the vanity making the room easier to share, for example.

If there is really only a little over two feet between the shower and tub, that is tight. Do you really need a separate shower and tub in that room?

IMO you do not have space for a free standing tub since min. 12" all around for cleaning and even then you will need to be in the tub tto clean. I think in thta size space a tub/ shower combo would be much better and if kids are using the larger bathroom do not bother with towel bars just use hooks .

Not sure how important "flow" is in a bathroom. I would turn the shower so the long wall is along the back, then put a drop-in tub in a tiled platform adjacent to the shower. This would allow the vanity to be longer, maybe enough for 2 sinks. If you need more length to the shower, some room could be taken out of the linen closet which really only needs to be about 18" deep.