Jessica Simpson has revealed she and fiance Eric Johnson are expecting a baby girl.

"She," Simpson, who will serve as a celebrity mentor for the fashion designers on NBC's upcoming Fashion Star reality competition, told ELLE magazine of her baby when she posed nude for the cover of its April 2012 issue.

Simpson and the former NFL player have reportedly picked out a name for their baby already but are waiting to make the announcement.

"We're sure [of the name]," Simpson, who previously starred in VH1's The Price of Beauty and MTV's Newlyweds reality series, explained, according to Us Weekly. "We're embroidering it on things. It's nothing shocking and nothing you'll have to add to the dictionary. When people hear it, they'll know why."

The 31-year-old mom-to-be reportedly said one of the biggest obstacles she had to face since becoming pregnant was cutting alcohol out of her diet.

"Givin' up my Scotch? My Macallan 18? That was hard for me! Though now being pregnant, you crave other things. A big thing of water sounds great!" Simpson added.

The reality TV star confirmed she was pregnant with Johnson's child in October, however reports that Simpson -- who had sported an increasingly prominent baby bump -- was expecting her first child dated back to late summer. She has said she learned she was pregnant on September 12.

Fashion Star will premiere Tuesday, March 13 at 9:30PM ET/PT.