First-time mom-to-be Vienna Girardi is expecting twin girls.

The 31-year-old Bachelor Season 14 winner confirmed her unborn babies' sexes in an interview with Us Weekly after announcing she's pregnant with twins.

"Truth be told, and this is crazy, but I've always wanted twins," Girardi told the magazine. "Finding out that I was having them was one of the most amazing moments of my life. They'll have a built-in bestie for life."

"Honestly, I wanted girls," she added. "I thought they were boys until I started picking out nurseries. I put pictures side by side and I looked at them and realized I picked out seven girl nurseries! It was psychological."

"I have four [names] picked out," she shared. "Now that I know they're girls, I'll say the names out loud like I'm talking to them and figure out what sounds best."

Girardi announced her pregnancy in June posting a photo of her twins' sonogram on Instagram, but didn't share the identity of the babies' father. She told Us Weekly she has the support of her mom and other family members.

"Three of my cousins and two of my best friends are pregnant right now," the star said. "It's nice because our kids are going to grow up together -- and I get maternity clothes passed down. My mom is going to live with me for the first two months to help with the babies."

Girardi split from Bachelor star Jake Pavelka in 2010 after getting engaged to the pilot on the Season 14 finale. She shared a photo of her growing baby bump in July, writing, "My little lemons. #2ndtrimester."