"Loving my little niece," Seewald Tweeted, along with a photo of her holding the 3-week-old baby in her arms.
Seewald's brother Josh Duggar and his wife, Anna, announced Meredith's birth via social media on July 19. She is the couple's fourth child, after daughter Mackynzie, 5, and sons Michael, 4, and Marcus, 2. On Wednesday, Josh and Anna were photographed eating dinner out with Meredith in tow.
Jessa Duggar's Father-in-Law Pens Essay in Wake of Josh Duggar Molestation Scandal: 'I'm Rooting for You'
Jessa, 22, is nearing the end of the second trimester of her pregnancy and she and husband Ben, 20, are "counting down the days" till their baby arrives.
Earlier this year, Jessa and sister Jill (Duggar) Dillard, 24, both admitted that they'd been molested by Josh when he was a teenager. The family's show, 19 Kids and Counting, was axed shortly after the molestation allegations became public but the sisters are scheduled to appear in a TLC documentary about sexual abuse.