07/17/2009 at 03:00 PM EDT
is officially M.I.A.: Mending inside anonymously.
While Tony Romo has made the rounds shopping, clubbing, gambling
and golfing since he dumped the singer last week, Simpson, 29, has kept a low-profile since the breakup
"She is still with her family," says a source close to Simpson, who is thought to be holed up at her parents' house in Encino, Calif. "She is surrounding herself with a network of support."
Soon, however, the newly minted bachelorette, may be ready for more company: The singer is expected to attend the star-studded birthday party for producer Billy Clark in Los Angeles on Saturday hosted by Simpson's friend Christina Milian.
Even if she skips the red carpet and opts to stay home, Simpson will eventually have to come out of hiding in August when she starts working on her new VH1 series The Price of Beauty
, in which she will chronicle the extreme lengths women go to maintain their looks.
Meanwhile in Lake Tahoe, Romo was spotted enjoying another round of golf on Thursday morning to prepare for Friday's American Century Championship tournament.
When asked by a fan how he was doing, the quarterback simply replied, "Good."
Reporting by K.C. BAKER and MARK GRAY