Jill Dillard is sharing in the joy of her sister's pregnancy announcement, and enjoying her time as a new mum.

On Tuesday morning, Jill posted a new photo of her son, Israel David, swaddled and sleeping as he was being held inside a car.

"So in love with our little guy #IsraelDavidDillard #babydilly," she wrote.

Israel was born on April 6, about 10 days past the due date. The healthy baby weighed 9 lbs. and 10 ounces, and was 23 inches long. Not surprisingly, he was delivered via C-section.

"We told the doctor, 'Stitch me up really well,'" Jill told PEOPLE last week.

The Dillards are already looking forward to having more children, and Jill expressed hope for a natural birth in the future.

About an hour after posting her photo of baby Israel, the 23-year-old wished congratulations to Jessa and Ben Seewald on their pregnancy announcement. The Seewalds announced on Tuesday that they are expecting their first child.

"Babies are such a blessing! #jessaseewald #babyseewald #pregnant," Jill captioned an Instagram photo of her sister and brother-in-law displaying their new baby bump.

Jessa, 22, and Ben, 19, said they cannot wait to be parents.

"We are so excited," Jessa told PEOPLE. "The due date is November first, our wedding anniversary."

"We are trying to take it one day at a time," said Ben. "We pray every night that God helps us be good parents. We are getting advice from other parents."

Pregnancy rumours swirled during Jessa's first trimester, as baby bump sightings and maternity clothes shopping were reported on her family's social media accounts.

Now, the Seewalds can relax and enjoy their final months as a twosome.

"I think having this first year together to share our lives, just the two of us, has been special," Jessa admitted. "We are definitely excited to be parents."