So Parker Posey and Lauren Ambrose are playing sisters in a new Fox sitcom called The Return of Jezebel James.

Sisters, huh? If you say so.

Posey is best known for her stellar work in a string of Christopher Guest "mockumentaries" such as For Your Consideration, Waiting For Guffman, Best in Show and A Mighty Wind. Ambrose is best known for her role as Claire in Six Feet Under. So they have the ability to act like sisters, no problem.

It's just that Posey and Ambrose look about as much like sisters as Jay Leno and Conan O'Brien look like brothers.

Ambrose actually got slightly snippy when we asked her about it. Not outright grumpy -- no need to overstate it. But you could hear a level of impatience creeping into her voice.

"I don't know. Creative licence. Different dads. I don't know. Milkman. I don't know," said Ambrose, who apparently doesn't know.

Did the producers of The Return of Jezebel James ever approach Ambrose about dying her red hair, to bring her more in line with Posey's dark locks?

"My mother would kill me," Ambrose said, with a lighter lilt. "She told me when I was little, 'You can do anything, just don't dye your hair, because it will never come back.' "

Gee, is that true? Great news for prematurely grey men everywhere!

Anyway, The Return of Jezebel James, which was created by Amy Sherman-Palladino (Gilmore Girls), debuts Friday on Fox with back-to-back episodes. Friday is a pre-ordained "death night" for TV (Saturday is the only night that's worse), so that tells us all we need to know about how much confidence Fox has in this sucker.

Posey stars as Sarah Tompkins, an editor of children's books who is single but hears the biological clock ticking. Upon learning she can't have kids, Sarah tracks down her estranged, bohemian little sister Coco (Ambrose) and broaches the subject of Coco carrying a child for Sarah.

Posey, of course, has been dubbed the queen of indie films, but she insisted she never has been anti-TV.

"When I was watching The Mary Tyler Moore Show as a child and my mom was in the next room, me and my brother would go, 'Mommy!' when (Mary) threw up the hat and we'd run and kiss the television," Posey recalled. "And then Buffy and Jody (of Family Affair) would come on, and we'd grab hands and do a little Buffy and Jody dance."

You know, The Return of Jezebel James could use a Buffy and Jody dance.

Posey is delightful when you meet her in person, but Sarah seems to have inherited none of Posey's charm. Sarah is too frantic, like a self-centred, hyperactive schoolgirl. She is not someone you will be cheering for right away.

And Ambrose? We really aren't sure if she's a comic actress at all.

Ultimately, audiences may conclude that the awkward feel of The Return of Jezebel James can't be fixed with a simple dye job.