On Sunday, the somber superstar, 41, turned up at MILK studios in Los Angeles for a photo shoot for a fall ad campaign for her Kohl's clothing line.
It's the first sighting of the singer, actress and "American Idol" judge since she and Marc Anthony announced their separation on Friday after seven years of marriage and two kids (twins Max and Emme, 3).
There were clues of a rift last weekend in Hollywood, when Lopez showed up without her hubby, 42, and without her wedding ring, at the BAFTAs Brits to Watch 2011 gala, where she and mom Guadalupe mingled with Prince William and Duchess Kate.
Latin crooner Anthony, meanwhile, was also getting back to work on Sunday. Performing before a huge, adoring crowd at the Parque Simon Bolivar stadium in Bogota, Colombia, Anthony made one cryptic allusion to his romantic status.
On Monday, a source confirms to Us that Lopez is set to fly out of the country — to the Ukraine, where she will sing for a private wedding on Tuesday.