Be very careful of ordering this way. I once knew a woman who ordered on line claiming they were able to make a replica ( it wasn't a Maggie dress) and when she got it, it was nothing like the website advertised. On the Maggie Sottero website, there is a disclaimer regarding ordering her dresses from non authorized dealers. I'm not sure I would take the risk!!
I've done a bit more research and www.mydress4less.com is an authorized dealer of Maggie Soterro and all the other designers carried on the site. All their dresses comes with certificates of authenticity :D
Only downfall is all the dresses are final sale. So it looks like going into a boutique locally and being fitted is a must.