Katie is still in New York at the mo filming more parts for Gossip Gril and she was on set on Ocober 07th filming in the exact same blue ballgown that Taylor Momsen and Blake Lively were wearing days before, Why you ask were this may help.
Cue the horror music: Little J is back on Gossip Girl and totally going all Single White Female on Serena! How else can you explain the photos that were just snapped on set of Taylor Momsen and Blake Lively wearing the exact same ballgown? Actually, we have the inside scoop from sources. But first a warning: Spoiler Alert!
According to my source, Jenny’s same-dress (and in one photo, she’s wearing a mask!) masquerade is all part of Juliet’s (Katie Cassidy) master plan to take down Serena. Yeah, in case you haven’t figured it out yet, Juliet is out for some cold hard revenge, and I’m told she’ll end up recruiting not-so-little-anymore Jenny Humphrey—and another major character—in her grand scheme. Any guesses on who that other character is? I’m all ears…
source: E!Online