Does anyone know how Rachel Roy sizing normally runs?

I've got my eye on a lovely Rachel Roy dress I came across recently at nordstrom.com. Unfortunately, according to the online store locator, the dress is not stocked in my usual size (or the next size down) at any of the Nordstrom stores close to me, so I can't try it on. Also, the size chart for the dress on nordstrom.com conflicts with the size chart on the Rachel Roy website by a pretty fair margin (by an inch or more per measurement).