The Client List star is clearly proud of her burgeoning bump, showing it off in a slinky dress that matched her sassy new fringe and jet black locks, which were significantly shorter than usual.
Her sophisticated look was completed with a pair of glamorous yet comfortable-looking leather platform wedge heels, giving a boost to her 5ft 3in frame.
The 34-year-old, who is expecting her first child with co-star actor Brian Hallisay, embraced motherhood by attending the Pampers Celebrates Love, Sleep and Play event at New York's Grand Central Station.
Before heading out, the pretty brunette took to Twitter to post a picture she snapped of herself pouting at the camera. "Proud to join @Pampers today to celebrate Love, Sleep & Play!" wrote Jennifer.
In a recent interview with Us Weekly, the actress revealed that she is working hard to keep fit during her pregnancy, working with a trainer doing "cardio and weights so my arms are strong to hold the baby."
She also spoke about impending motherhood: "I think most people, when they're getting ready to be a mom, they go, 'Oh my gosh, I have to have all of the answers right now.'
"But every kid is different, every parent is different and every child and parent relationship is different, so you just sort of have to wait until you're in it and do the best that you can to try to be zen in the middle of it all."
The actress announced her pregnancy to Us Weekly in June. "We're so thrilled and happy to start a family," she said, adding that she was about three months along. A day later, she added to the good news, sharing that the parents to be were also engaged.
Brian, also 34, proposed while the couple were on holiday in Italy. The two met when filming the NBC drama Love Bites and have been together for about a year and a half.