The former UFC Women's Bantamweight and WWE Raw Women's champion shared a photo of the baby breastfeeding inside her shirt and another with her daughter touching Browne's tattoo on her verified Instagram account on Monday (September 27).
"We're keeping it simple, we're keeping it safe, we're keeping it Browsey Acres style," Rousey revealed before feeling what appeared to be her baby kicking while walking alongside Browne on their family farm.
The video then showed a Nintendo style egg hatching to reveal a sonogram of the couple's child followed by a Pokémon video game style caption of "It's a Girl!" and a background jingle.
Rousey initially announced her pregnancy in a video shared on her YouTube account in April.
"I've been pregnant since January so four months, woo, baby bump, and I just wanted to share with you guys a little bit of the journey we've been on," Rousey said in the video.
Rousey's initial video announcement included footage of herself and Browne going to the doctor's office.
Rousey is one of the most recognizable names in UFC history and regarded as a pioneer of women's mixed martial arts.
The former judo champion was the first female fighter to sign with the UFC in November 2012 and went 12-0 (6-0 UFC) -- nine victories coming in under one minute -- during her first 12 professional MMA fights.
Rousey finished her MMA career with a 12-2 record following losses to Holly Holm in November 2015 and Amanda Nunes in December 2016.
Rousey then made the transition to professional wrestling, making her in-ring debut for WWE at WrestleMania 31. The Riverside, California native held the Raw Women's championship for more than 230 days before being defeated by Becky Lynch at WrestleMania 35, which was the first all-women's WrestleMania main event and her last appearance with the company.
Rousey confirmed she left WWE with the intention to start a family at the time of her departure.
Browne also has two other children from a previous marriage.