Here is a Tumblr blog where they are matching up the canon clothing worn by the characters to the real life clothing. I am going to add the outfits to the
Canon Post Main List: Season 1 Ep 1-9 Click Here for Catcentstyle Tumblr! They are also requesting help. If you know what designer or website sells a certain outfit or item, post it here then let Catcentstyle know or I will use your post to tell them.
Example: Catherine and her sister wore J-Crew arabelle gowns as bridesmaids at their fathers wedding in the episode, Bridesmaid Up [1x09] $365