Gossip Girl star Taylor Momsen has already been absent for most of the first half of this season. Now it looks like she'll be MIA in much if not all of the second half, too.

The controversial actress and singer, who has appeared in just three episodes so far this fall, begins an "indefinite hiatus" following next Monday's episode, "Gaslit."

Reps for The CW and producer Warner Bros. declined comment, but sources confirm that Jenny Humphrey will be MIA for at least four episodes after "The Townie."

That's the December 6 episode and the show's midseason finale.

Are Jenny's Gossip Girl days numbered?

The news comes as the 17-year-old Pretty Reckless singer's off-screen persona - flashing crowds, profane tirades, generally miserable nature - continues to raise eyebrows.

Momsen also pissed off Project Runway's Tim Gunn, who played mentor to J in an episode last month, after which Gunn blasted her for a lack of professionalism.

A Gossip Girl insider maintains that reduced airtime for Momsen, an original cast member who has been on the show since the pilot, is due only to creative reasons.

We're at least a little skeptical of that, given all Jenny brings to the show. Do you think it's because of her off-set behavior - and do you think she'll ever be back?

Jenny Humphrey on Gossip Girl:

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.