With about four months to go until Jessica Simpson gives birth to her second child, insiders say she may have already selected a name: Ace.

Jessica and her fiancé Eric Johnson are said to have told friends about the name decision, The Daily Mail reported, but they haven't explained the inspiration behind it. A source apparently made the big reveal to Us Weekly Magazine.

The couple, already parents to nine-month-old daughter Maxwell Drew, is reportedly expecting a baby son.

The name Ace was made famous by Jim Carrey's character in the 1994 movie, "Ace Ventura." It means "one" or expert.

While Jessica awaits her second child's birth, she is focused on her daughter Maxwell, marveling at some of the things she mastered at such a young age.

She tweeted on Tuesday: "Maxwell can whistle on cue at 9 months! Heck I'm still learning! This lil human impresses me everyday."

And on Feb. 1, she tweeted a picture of her daughter with the caption, 'My lil dollface is 9 months today!'

Although Jessica and Eric have not publicly announced their name choice, insiders were correct in predicting their daughter Maxwell's name.

Once Jessica discussed Maxwell Drew's name, she said it was meaningful but not "shocking." Her name is a combination of Eric's middle name and grandmother's surname, along with Jessica's mother Tina's maiden name.

"It's nothing shocking and nothing you'll have to add to the dictionary," she said. "Still, when people hear it they'll know why."

Jessica took Maxwell out to lunch in Studio City in Los Angeles on Thursday, smiling as she held the little girl.

But she likely stuck to a salad at the Mexican establishment -- because she gained 70 pounds during her first pregnancy. But the weight gain wasn't all bad news for Jessica -- she managed to bag a multimillion-dollar deal with Weight Watchers, becoming a spokesperson for them as she lost the weight.