Credit: Jason LaVeris/FilmMagic

Are Taylor Momsen's Gossip Girl days over?

The increasingly controversial 17-year-old actress will begin an "indefinite hiatus" from Gossip Girl following next Monday's episode, sources tell Deadline. Reps for the CW and Warner Brothers declined to comment.

Momsen has played Jenny Humphrey, kid sister to Dan Humphrey (Penn Badgley) since the CW soap debuted in 2007. Although a series regular, she has only appeared in three episodes so far in the current fourth season.

"She only does [the show] for the money," a source explains to  "She works hard on Gossip Girl but doesn't care about the plot or the other cast members. She treats it like a 9-5. No emotional investment."

Momsen, who also fronts the rock band Pretty Reckless, has grown up since her big-screen debut at age 7 as cute Cindy Lou Who in How the Grinch Stole Christmas -- raising eyebrows with her skimpy, intensely Gothic wardrobe, notoriously foul-mouthed interviews and angry, age-inappropriate antics.

The new Us Weekly even reports that, for her Oct. 21 Pretty Reckless concert at NYC's Don Hill's (in which she flashed her breasts to the crowd) Momsen had a startling request: "Her rider included a full bar in her dressing room," an insider told Us. "That was rejected -- she's underage!"