Kourtney Kardashian and her 18-month-old daughter Penelope Disick wear bikinis while vacationing in Mexico. Credit: Splash News Online

Baby in bikini! Kourtney Kardashian showed off her trim beach body at the pool in Mexico on Jan. 23, but her 18-month-old daughter Penelope Disick stole the show in an adorable zebra-print two piece with pink trim from PilyQ Barcelona called the Simba Ruffle Bikini. 

Along with big brother Mason Disick, 4, Penelope seemed to be having a great time on the family outing, holding her mother's hand as she walked around the pool. 

Kardashian, 34, looked fit and chic in the Zella Demi bikini by A.Che Swimwear, wearing giant gold earrings and shades while soaking up some family time. 

"It was harder to lose weight the second time around," Kardashian admitted to Us Weekly in January 2013. "I gained 45 pounds with Penelope."

But thanks to fitness pro Tracy Anderson's 90-minute, dance-focused workouts and smaller portion sizes, she was able to drop the weight in no time.

Longtime boyfriend and baby daddy Scott Disick was no where to be seen in the photos, but he was nearby. The family is staying at Joe Francis' home, Casa Aramara, in Mexico.  

Disick, 30, has recently struggled with the loss of both his mother Bonnie in November 2013 and father Jeffrey in early January.