Congratulations are in order for Anna Duggar's sister Priscilla Waller. The stay-at-home mom just revealed she is expecting her fourth child with husband David — and Anna announced it's a girl! The former 19 Kids and Counting star took to Instagram to share the exciting news.

"It's a girl!!!!" she wrote on Sunday, April 23. "Congratulations David & Priscilla!"

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It’s a girl!!!! Congratulations David & Priscilla!

A post shared by Anna Duggar (@annaduggar) on

Alongside their three kids Paul, 5, Davia, 3, and 17-month-old son Phillip, David and Priscilla revealed that they are 15 weeks pregnant and the new addition will arrive sometime in September. "We praise the Lord for the gift of life and are praying for a healthy baby and mommy and a safe timely delivery," the couple captioned the video on Instagram last week. "Paul and Davia are thrilled! Phillip is so happy that they are happy, but I don't think has any idea why they are so happy." Watch the video above to see the adorable announcement!

Of course, fans of the family were also loving the pregnancy reveal. "I'm so happy for you! I'll bet Davia would love a little sister this time! Congratulations," one follower wrote. Another agreed, adding, "Oh my goodness what wonderful news that you guys are having another baby, congratulations. Hope Priscilla's pregnancy is going well and smoothly."

This new addition means Priscilla is slowing catching up to Anna when it comes to their family size. Anna just welcomed her fifth child with husband Josh Duggar last September, a son named Mason Garrett Duggar. The baby boy joined older siblings Mackynzie, 7, Michael, 5, Marcus, 4, and Meredith, 2. "The entire family is ecstatic over the arrival of another beautiful blessing," Josh and Anna said at the time. "We want to thank everyone for your prayers, kind words and well wishes. We appreciate it much more than we could ever express. We pray God blesses each of you with an abundance of the kindness you’ve shown us."

Anna is one of seven siblings, and along with Priscilla, has sisters Esther, Susanna, and Rebekah, and brothers, David, Daniel, and Nathen. Having a hard time keeping them all straight? No worries, here's a visual guide to the Duggar family tree. You can thank us later.

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