She’s musing about becoming a grandmother and not ruling out plastic surgery as she turns 50 on Friday. But Michelle Obama can still “shake a tail feather” and plans to as she celebrates the milestone the next day at the White House.

The invite to “Snacks & Sips & Dancing & Dessert,” obtained by a hometown newspaper, the Chicago Tribune, says guests have been told to wear comfortable shoes, practice their dance moves and eat before arriving.

The White House wouldn’t divulge details, but it coyly tweeted a picture this week of the first lady and the president cutting the rug in the White House, along with the words “Let’s dance.” Reporters at the White House on Thursday spotted boxes of champagne arriving.

Obama boasts that she’s the dancer in the family, and longtime pal Donna Brazile told the Tribune she’s expecting to lace up her dance shoes. “That woman can still shake a tail feather,” she said of the first lady.

Obama offered a hint during a recent visit to the Children’s National Medical Center in Washington when a 12-year-old – and fellow Capricorn, the first lady noted – asked how she planned to celebrate.

Obama acknowledged that she’d be turning “50 and fabulous.” As for the party, “I’m not exactly sure yet what I’m going to do,” she said. “But it might involve some dancing.”

The White House has sought to swat down rumors fueled by a British tabloid that British crooner Adele and Obama’s pal Beyonce – whose husband, Jay Z, was to perform in Washington on the eve of Obama’s birthday – will sing at the private party.