It’s been a long time since we’ve heard anything from Jamie Lynn Spears, Nickelodeon star-turned-safe sex poster child.

It looks like big sister Britney isn’t the only Spears woman who locks changing up her locks and taking a walk on the wildside as a brunette. Jamie Lynn, 18, rocked a black wig and engaged in a bit of underage drinking and partying with pals at the Atlas Bar in Hammond, Louisiana last month, spywitnesses reveal in the Jan. 25 issue of Star Magazine.

“Jamie Lynn has been out partying in Hammond several times in the past month or so,” says a tipster.

Despite her raven-headed disguise, J.L.’s cover was blown by the noisy bouncer who checked her ID at the door: “The bouncer told everyone who she was,” blabs another partygoer. “She had a friend who was over 21 buy her shots and drinks.”

Jamie Lynn dropped out of the national spotlight after welcoming daughter Maddie Briann with fiance Casey Aldridge in the Summer of 2008.