I love that eshakti dress. Did you notice it's customizable? It's a little bridesmaid'y, but the price is great, and if she wants to adjust the length and the sleeve, even the neckline, she can! Frankly I think I'd be suggesting that to her sisters and they can each have the size shape and style they want for low cash and a consistent look.
I also liked this one
http://www.eshakti.com/Product/CL0027392/Taylor-dress
You can do it with or without the embellishment if the roses are a bit much for you.
(The picture post is not working right, so hopefully you can use the link to find the dress)