Jessa Seewald (née Duggar) and her husband Ben both welcomed their first child together last November, and the couple is still adjusting to the change of becoming first-time parents - which will be documented on the new season of TLC's "Jill and Jessa: Counting On," a spin-off of the Duggar family's former reality TV series "19 Kids and Counting."

"Jill and Jessa: Counting On" will also focus on the other, oldest Duggar children. Jessa's 24-year-old sister Jill Dillard (née Duggar) and her husband Derick Dillard, 27, check in from their missionary trip to South America with their infant son Israel. Also set to appear during Season 2 of the TLC series are Duggar sisters Jana, 26; Jinger, 22; Joy Anna, 18; and Duggar brothers John David, 26; Joseph, 21; and Josiah, 19, as they adjust to adulthood.

In a sneak peek for tonight's season two premiere, Jessa and Ben open up about the delivery and birth of their son, and explain how their lives have changed since they welcomed 4-month-old Spurgeon into the world. In the clip, Jessa dresses little Spurgeon for a visit to the Duggar home.

"Today we're going over to my family's house and Jinger's gonna do our first family photo shoot," Jessa tells the cameras as she hold little sleeping Spurgeon.

The couple double checks that they have everything they need before leaving for their photo shoot, and Jessa suggests they bring an extra change of clothes incase Spurgeon soils himself.

"Transitioning from a family of two to a family of three-there's a lot of changes in there," Ben says in the couple's joint on-camera interview. "There's just the aspect of taking care of another person, it takes longer to get out the door but it's a good change."

"Having a lot of younger siblings around, I learned how to change diapers, dress a newborn and that sort of thing so I wasn't really nervous in that way," Jessa explains. "But I know having the full 24-hour care of an infant is something that's way different than being like, 'Oh, there's a dirty diaper, here you go mom.' You know? It's like, every diaper change, every feeding is all on you."

Watch the full sneak peek below and be sure to catch the Season 2 premiere of "Jill and Jessa: Counting On," airing on Tuesday, March 15 at 9 p.m. on TLC.