"Gotten to spend a very sweet week with our newest addition.. meet our girl Baylah May Foehner," Barrett wrote on Instagram.
Cade Foehner also shared an Instagram message about the newest addition to the family.
"The Lord Jesus has given me so much that I scarce can believe it," Foehner wrote. "Not only to be saved from sin because of His Gospel but to also be given a Wife who is not only my best friend in the whole wide world but who also has bore me a child.
I am a blessed man beyond my understanding."
The couple announced to PEOPLE that they were expecting a baby back in August.
"We are very excited," Barrett told PEOPLE magazine. "The Lord has blessed us with a little one, and we're really excited to finally be able to share the news with everybody and just have a big old family celebration about it."
Barrett, 20, and Foehner, 24, married in October 2019. Barrett told PEOPLE she found out she was pregnant in May.
"We were in Texas visiting Cade's side of his family," Barrett said. "And it's funny, because I did not think that I was. Around lunchtime, I remember taking the test and my eyes nearly crossed! I was like, 'Wait, is that two lines?' I came running out to Cade and was just like, 'Oh my gosh, I think I am.' That's all that I said, and he knew what that meant. I started crying, and it was very sweet."
Barrett finished in third place on season 16 of American Idol. She released her debut album Goldmine in June. Foehner was eliminated during Top 5. He's now performing as a solo artist.
Barrett hit No. 1 in 2020 with her song "I Hope." Along with rising country artist Ingrid Andress, Barrett made Billboard chart history as the first time in the chart's 30 year history that two women's debut singles simultaneously made the top 10.