I gave in and ordered the Darby Dress from Baukjen and it is perfect!
here
Just below knee and really gorgeous - casual but flattering. I'm 5'6 and found the Becca dress ridiculously short on me and just looked a bit tarty and awkward, but I love the style (also I know that Hush dress is similar but everything Ive had from Hush has been such a waste of money - expensive and washed badly).