I would look at this room from 2 angles, in this order: convenience (as you have young kids and need everyone to be able to fully use it) and aesthetics. Equipment and accessories: #1 - first look at what is necessary to have in this bathroom: a place where to keep soap, toothbrushes, toothpaste -- all within easy reach for all users (including not-tall-enough kids) #2 - a cosmetic mirror ? #3 - a towel rail #4 - a small cabinet for storage Ideally, #1 should be stored directly on the sink, as it's lower, within easy reach for the kids (see below photo from one of our baths): You can do this also witha smaller sink, like the one we use in the half-bath: If you'd like to keep the one you have (which is really nice), you'll have then to use a shelf (as also suggested by someone else above), and I'd propose one of white porcelain and not one of glass, as it's a lot less reliable with children around. Below, an example of what I mean. The shelf should be installed as low as possible to be reachable by the kids, but also the mirror should be much lower, so that they can use it (much more interesting for them) without having it too low so the adults can't see themselves anymore. For #2 look on the left of the mirror in this photo (if you need it): A towel rail (#3) is absolutely necessary and make sure it's one where you can stretch the towel for faster drying (like the one in the 2nd photo). The cabinet storage (#4) could be placed on the wall from the right of the mirror, as you can see we have in our half-bath (also 2nd photo): Aesthetics: I agree that blinds on the window make no sense, light should be let to flow in as it's much needed in a bathroom. If you don't have time or disposition to paint the walls (and maybe they should remain white anyway, or a light color, because this is a small space), you might use decorations from your DYI center and stick them on the walls (see an example below from my daughter's bedroom, but there are other smaller ones for any kind of space): This way, the room becomes more attractive, more welcoming and more colorful (with very low cost). I hope this helps :-)

I would wait for the rug, until you have the shutters up and your furniture placed..it may take on a character of its own and you'll want to compliment. My first thought though was to coordinate with your kitchen and incorporate some black, with a black/beige stripped rug, which would be fun with the wallpaper and perhaps paint your chairs black, add the shutters and you could paint the window trim black and add a large black chandelier.

This made me laugh: http://www.theguardian.com/environment/2016/jun/09/seagull-turns-orange-after-falling-into-vat-of-chicken-tikka-masala I couldn't copy the picture, but it's hilarious.

You might paint the walls a bold color you really love, but I would recommend staying away from wallpaper as it is costly and too difficult to change. I agree with another poster that wider trim around the doors would help, and I would suggest that you paint all the trim white and add crown molding and a mop-board along the floor-wall junctures. I love the wood-tone door and would keep it as an accent piece and for contrast. You might add large, framed mirrors to the walls to reflect light and perhaps add a console table with a fairly large lamp. An interesting print area rug also can add pizzazz to this space. If you can use the bold wall color as an accent throughout the house, it will help to tie the entire color scheme together and give your home a unified look. In the offset hallway shown in Photos Two, Three, and Four, I would suggest you place a desk and chair and/or perhaps some bookcases and curio cabinets to make an interesting entrance way that can double as a study or home office. As an alternative, you could place a narrow dining table with leaves that fold down to allow easy traffic through the hallway. Above the table you could display some framed mirrors and, in matching frames, family photos that can serve as conversation starters. When you entertain, the fold-down dining table could be pulled out and/or moved to another room to accommodate your guests.