The Duggar family is welcoming another addition to their constantly growing family by celebrating the news of Anna Duggar's older sister, Priscilla Waller, expecting her fourth child.
Waller and her husband David announced the news on their blog, David Loves Priscilla on Thursday.
"While, [David's sister] Lydia was in town, we told our immediate family the great news that we are expecting baby number four sometime in late September," the couple shared on Thursday, David's birthday. "We are so excited to welcome this little one into our arms. The children are absolutely elated."
The couple said Anna will throw a baby reveal party later this month to announce the baby's gender.
David also posted a video on his Instagram page, where fans congratulated the couple on their new addition. The baby will join Paula, Davia and Phillip.
"I'm so happy for you! I'll bet Davia would love a little sister this time! Congratulations," one person wrote.
"Congratulations!! Children are such a blessing and so thankful for them! Congratulation!! You two make amazing parents," another fan added.
"Congrats that's great to hear may the lord keep on blessing you and your growing family, I love watching your family grow and seeing all your pictures and testimonies and everything," another fan wrote.
Anna is married to Josh Duggar, and has her own big family. Josh and Anna have five children, whose names all start with "M" - Mackynzie, Michael, Marcus, Meredith and Mason. Their youngest, Mason, was born in September.
Other members of the Duggar family are expecting their first children. Last week, Jinger and Jeremy Vuolo announced that their first child is a girl.
Joseph and Kendra Duggar are expecting their first child as well. They shared a photo of Kendra's growing baby bump in March.
Earlier this year, Joy-Anna and Austin Forsyth welcomed their first child, Gideon Martyn.
Like her husband Josh, Anna Duggar comes from a big family. Anna and Waller have five other siblings. Waller and David have been married since February 2012 and have traveled to the Philippines, Romania, Australia and throughout the U.S. together, according to their website. Like the Duggars, they believe in strong Christian values and were both ministers.
"We always enjoy a little adventure and if someone says that something cannot be done, that gives us all the more motivation to try," reads a statement on their site. "We enjoy playing pick-up sports such as volleyball or soccer with fellow young people and are always up for a couple mile jog or a nice long bike ride together."