A lot of neat ideas were brought up on this thread.
But as a mother myself, when I read that your wife will be bathing little children in there, I think about the practicality of that bathroom as your little children become bigger and bigger children, and teens.
What comes to mind is lots of storage. If the linen closet is some ways away, then I would put in shelving or cabinetry for towel storage. Also, lots of towel racks might come in handy.
Kids need to be able to see in the mirror to brush their teeth. So, either the mirror needs to come down fairly low (requiring more cleanup from splashing, ugh) or the kids will need a stepstool. Storage for the stepstool, rubber duckies, and so on could be under the sink if you choose a cabinet sink but if you plan to have a pedestal sink you may need more storage somewhere. You may need to plan on room for a hamper, too.
Additionally, with growing kids who will eventually morph into teens using the bathroom I would suggest choosing some very easy-to-clean surfaces that don't show dirt.