TVLine commented in a recent scoop about the possibility of Zooey's real-life sister, Emily Deschanel "popping over" to New Girl to play her TV sis, coming up this season (3):
Similarly, don’t expect Emily Deschanel to pop over to her sister’s neck of the woods to play Jess’ soon-to-arrive sis. “Emily works huge hours a week,” Hanson stresses. “And she has a baby to take care of too. I don’t see how she could possibly do it. It would be great [publicity] for us, but I just don’t think that there’s a human being in the world who could do it.”
Sad face? :(
UPDATE: New Girl executive producer, Brett Baer previewed to TVLine a little more details about Jess' sister in season 3:
When Jess’ hellion of a sister turns up in early 2014, she will “add a depth charge in the fabric of the loft,” previews exec producer Brett Baer. There’s also a chance she’ll look a lot like Zooey Dechanel’s real-life sis, Emily. Not a great chance, mind you. But a chance nonetheless. “It’s an idea that is obviously right in front of us and it’s definitely something to explore,” concedes exec producer Dave Finkel. “But [Emily] has her own television show, so we’re not sure if it’s even a possibility.”
UPDATE: New Girl creator, Liz Meriwether tells Entertainment Weekly that the character of Jess' sister, "won’t appear...until a few episodes in[to season 3]" and that "the loft better prepare themselves because the character will “wreak havoc on everyone’s lives.” EW also spoiled that Zooey Deschanel's TV sister will be an older sister. What havoc do you think this other Miss Day will wreak on the guys?
"Emily Deschanel is coming to New Girl! OK, not really, but wouldn't it be awesome if Zooey's real-life sibling played Jess' sister?..."
While it hasn't been confirmed whether Zooey Deschanel's sister, Emily will ever guest on New Girl, show creator, Liz Meriwether tells TV Guide that they are actually looking to cast Jess' sister for this upcoming season.
It's possible! We'll meet that character later this year, according to executive producer Liz Meriwether, and boy, is she trouble! "I have a feeling that Emily has a pretty busy schedule with Bones, [but] I'm excited to cast the sister; I think it'll be really fun."
Who would be your dream casting for Jess' sister on New Girl, Emily Deschanel - or somebody else?