Teen Mom 3's Mackenzie Douthit revealed the gender of her second baby via Instagram on Saturday, Sept. 14 Credit: Scott Gries

A little girl is on the way! Teen Mom 3 star Mackenzie Douthit revealed Saturday, Sept. 14, that she and her husband Josh McKee are expecting a baby girl! The two -- already parents to big brother Gannon, 2 -- celebrated with close family and friends for the big reveal.

"Find out what I'm having!" the second-time mom-to-be yelled into her phone during a Vine video. The newlywed then taped McKee slicing a cake to reveal the color pink inside.

"Josh cannot stop smiling. He's always wanted a little princess to look after," Douthit tweeted shortly after the reveal. "Now josh is calling all his rodeo friends to tell them #cutedadtweet."

The couple tied the knot in a country-themed wedding at The Barn at Timber in Pittsburg, Kansas on Aug. 17, as Us Weekly exclusively first confirmed. The high school sweethearts were feted by 200 guests for the special day.

"Today is the day I walk down thay aisle and marry my best friend....and the two shall become one," the Miami, Okla. native wrote at the time.

Teen Mom 3 airs Mondays at 10:00 p.m. on MTV.