'Jill & Jessa: Counting On' Sneak Peek: Jill Dillard Shares Her Excitement Over Having Mission Trip Special Guest

Jill and Derick Dillard made the bold decision to ditch their normal lives in Arkansas for missionary work in Central America earlier this year. The couple did not speak much on their decision — that is, until now. TLC has officially released a sneak peak for episode 2 of "Jill & Jessa: Counting On." In the new installment, set to air Sunday, the new mom reveals to viewers the one thing that made their big move a little easier.

As was reported by People magazine, Jill, 24, speaks candidly about their trip and all their preparations in the sneak-peek video. She reveals to viewers that Derick's mother, Miss Cathy, will be joining them for part of their journey. The occasion is especially "joyous" because Cathy had previously been in the hospital undergoing treatment for cancer. Jill says she and Derick, 26, are "really excited" for their upcoming journey and even more so to have her mother-in-law joining them.

"While Derick and I were engaged, Miss Cathy was in the hospital going through cancer treatments. Now it's a joyous season, with her grandson and just getting to share in that," Jill says.

Although Jill and Derick seem genuinely excited for what lie ahead of them, other members of their families are sad to see them go. Jessa Seewald, who was pregnant with her son Spurgeon Elliot Seewald at the time, is especially upset in the preview. Jessa, 23, opens up about her feelings on the couple's trip on the show, admitting that she is "really sad." She tells viewers she selfishly wishes Jill would be around to see her welcome her first child into the world.

Watch the sneak peek below:

"Jill & Jessa: Counting On" will tackle plenty of other major issues. Early previews revealed that Anna Duggar will also be appearing on the show and will discuss the scandals surrounding her husband Josh Duggar. Clips show Anna, 27, breaking down into tears while telling viewers she didn't want to believe that her husband had been unfaithful. She went on to say that she had been hopeful at the time that she would wake up to find it had all been a bad dream.

"Jill & Jessa: Counting On" airs Sundays at 8 p.m. EST on TLC.