I thought I posted this to the baths forum, but looks like I didn't. I'll put it there too.

How would you ever paint back in there? What about spills off the countertop running off the sides? If the bath is going to service 5 kids, something is going to spill there. Personally, I think it will look like something too big in a too small spot. Also, a vanity top would overhang by more than 1/2 inch, wouldn't it?

Jelly toast, do you think a smaller vanity would look better? Like a 30" that would leave 4.5 " on either side?

That's how I'd do it; either that or have the cabinet fill the entire space (built in). If I were using a free-standing vanity, I'd want enough space on either side to make future paint jobs feasible. You want it to look like you did it on purpose, not like "I just happened to get a good deal on this size cabinet so that's what I used."

Is there a decorating forum you could post to as well? I know some of the forums don't get much traffic. Maybe some others will chime in here.

What if you put wainscoting on the walls? I think you could get 1/2" thick panels. Could you live with a 1/2" gap?

Don't forget to account for your base molding too. We added it along the side when we changed to a furniture-style vanity.