The singer and her husband Marc Anthony both attended the afternoon shower, which was hosted by Elaine Goldsmith-Thomas, Lopez's producer on the 2002 film Maid in Manhattan.
Lopez, 38, "looked very pretty – and very pregnant," according to an eyewitness, who saw the couple arrive flanked by bodyguards.
Among the guests were actress Leah Remini and designer Roberto Cavalli, who gifted Lopez with a pink leopard crib, according to a source. As for the décor, everything at the shower was blue and pink – and the room was covered with Swarovski crystal, said the source.
Last month the singer, who is due in a few weeks, was given matching pink and blue Tuni & G onesies from her sister Lynda Lopez. The pop star has been mum about whether she's expecting twins, though multiple sources have told PEOPLE she's having two bundles of joy.
The singer first announced she would be starting a family with her husband of three years, Marc Anthony, 39, last November after months of speculation.
"This is a special time in our lives," Lopez told an audience during a concert in Miami, the final stop on the couple’s El Cantante tour.
Even as her baby bump grew increasingly noticeable with each performance, Lopez had avoided discussing her impending motherhood.
"We're just getting used to the fact that we've told everybody" Lopez tells Harper's Bazaar for its February issue.
When asked how long she is planning to take off from her career as a singer, actress and designer, Lopez says, "I don't know – and I like that."