Whitney and Zach are ready to share some happy news with the rest of the family – they have baby number 3 on the way! Whitney wants to surprise everyone, including Zach, with the gender and enlists Kelly Jo to come up with a covert plan. Josie and Kelton are busy decorating a nursery in Josie's signature "boho-chic" style and Carlin hits a big milestone before her wedding: college graduation! Later, Carlin and her bridesmaids go to see her pastel colored bridesmaid dresses in person, but will the bride-to-be cry tears of joy or disappointment?