Jessa (Duggar) Seewald and Ben Seewald welcomed their first child Thursday

By Aurelie Corinthios and Michele Corriston
Updated November 06, 2015 11:25 AM
Courtesy Jessa Duggar Seewald

Jessa (Duggar) Seewald is already an amazing mom, according to her brother-in-law.

Derick Dillard – her sister Jill (Duggar) Dillard‘s husband – congratulated the new mother on the birth of her baby boy Friday.

“Congrats to Jessa and Ben on the birth of their baby boy!” Derick, 26, wrote on Instagram. ” @ben_seewald @jessaseewald y’all are great parents already! May you raise this little guy in the love and admonition of our Lord. #congrats #newparents #newnephew #prouduncle.”

Jill, 24, is already mom to son Israel, who turned 7 months old Friday. She offered a celebratory message for her sister on Instagram, too, writing, “Yay! So excited for @jessaseewald and @ben_seewald.”

Jessa, 23, and husband Ben Seewald, 20, also took to their website,, on Friday to reveal an album of baby pictures of their firstborn.

The album contains six pictures of the baby, including one with new father Ben and another with happy grandfather Jim Bob Duggar.

Jessa and Ben welcomed their first child on Thursday, a healthy baby boy weighing 9 lbs. 11 oz. and 21 inches long. The new parents have not yet announced their son’s name.

The couple shared the first photo of their child exclusively with PEOPLE on Friday.

The Duggar family also posted a congratulatory message on Facebook.

“Yesterday Jessa gave birth to a baby boy. He is 9 lbs 11 ounces and 21 1/4 inches long. Both Jessa and the baby are doing well,” the Duggars wrote on their official page.

The birth of the new baby will be a focal point in Counting On, TLC‘s upcoming series of specials featuring Jessa and sister Jill’s lives now.