The two adopted children of Little Couple's Bill Klein and Jen Arnold were baptised during Tuesday night's seven seven premiere.

The baptism of Will, 4, and Zoey, 2, was a welcome moment of joy for Bill and Jen after some tough challenges, including her recovery from stage 3 cancer. 

In the TLC clip, Will is held over a baptismal font as church deacon Tom Stauffacher pours water over his head.

Jen's brother, David Arnold Jr and his wife Lisa were named the godparents of Zoey, while Bill's brother Joe Klein and his wife Karen were made the godparents of Will.

The ceremony took place at the Ascension Catholic Church in Melbourne, Florida.

"I was a little bit concerned about how Will and Zoey would take to the water being poured over their head, but surprisingly they did really well," Jen said.

Jen has been clear of cancer for nine months but the series revealed another stress for the couple with Bill needing back surgery.

"It turns out back surgery is a real pain in the butt to recover from, but I'm walking. ... I'm excited that we're getting back to some semblance of normal in the Klein-Arnold household," he told the Today show.

Jen added that it hadn't been easy to let the cameras in on her battle with cancer during season 6 but she came to feel it could be beneficial for others.

"I think once we had some time to digest the diagnosis, feel like we were on a path of treatment, and sort of had our heads wrapped around everything that was going on, it became clear to me that I did want to share it ... I hoped that it would help others who might be dealing with a similar situation," she said.

Jen told the show that she was raised by her parents to look at the ups and downs of life with a positive perspective and gratitude.

"Our parents were very much focused on the fact that, you know, life may be hard, and we have different obstacles than other folks, but we still have a lot to be thankful for," she said. "And the alternative to not being optimistic is a lot less fun."