'Teen Mom' 's Catelynn and Tyler Answer Daughter Novalee's Questions About Sister Carly's Adoption

Catelynn Baltierra/Instagram; Teen Mom/Instagram

Catelynn Lowell and Tyler Baltierra are broaching a big subject with their daughter.

On Wednesday's episode of Teen Mom: Next Chapter, Lowell tells her husband about their daughter Novalee's emotional state when she got picked up from school earlier that day.

"She just started sobbing," the 30-year-old mom explains to her husband. "She's like, 'I really miss Carly.' She's like, 'I don't — why did you have to separate us?' "

Lowell and Baltierra share daughters Rya Rose, 12 months, Vaeda Luma, 3, and Novalee Reign, 7. The couple also welcomed a baby girl, Carly, at 16 years old in 2009 and placed her for adoption, a story that unfolded on MTV's first season of 16 & Pregnant.

Later, the parents speak with their daughter about why she was so upset.

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"It feels like that's my sister and I can't see her that much," the second-grader explains, asking them to "imagine getting split up from your sister or your brother."

Novalee asks Lowell and Baltierra how old they were when they had Carly, to which they answer honestly. When Novalee learns they were just 16, she replies, "That's not a grown up!"

"You should be like 40 or something," she says, to which they both laugh and assure her 40 is a "great age."

Novalee then asks, "Why did you think about having a baby that early?"

RELATED: 'Teen Mom' 's Catelynn Lowell Recalls 'Anxiety and Being Very Scared' When Expecting Her First Baby

Jeff Kravitz/FilmMagic

"We weren't being responsible," Baltierra says. "We were making bad choices."

Later, the couple reflect on the conversation, with Lowell explaining, "It just never occurred to me, when I was making the decision at 16, how it would impact my future children, you know?"

Baltierra, also 30, feels the same, adding, "I guess I never really thought about it affecting them in a negative way."

Lowell and Baltierra met for the first time in 7th grade in Algonac, Michigan. In 2005, they began dating and tied the knot in August 2015.