The former First Daughter announced the news Monday on NBC's Today. Jenna and her husband, Henry Hager, are already parents to daughter Mila, who turns 2 on Apr. 13. Mia helped her parents announce the happy news, blowing a kiss to her "little sissy" in a home video that Jenna shared on the morning show.
Today's Savannah Guthrie, Tamron Hall, Matt Lauer and Natalie Morales celebrated Jenna's baby news by presenting her with a bouquet of flowers.