The Johnston family takes a line dancing class to prepare for Liz's upcoming 21st birthday, and Liz makes plans to move in with Brice. Then, the sisters have a sleepover while Trent and Amber debut their new bathroom.

Trent and Amber prepare Alex for his first solo trip to visit his girlfriend, Allie; Elizabeth and Brice look at a rental home; Jonah tries to help Anna deal with stress using meditation; Trent begins a journey to get in shape.

Alex's girlfriend, Allie, arrives in town for the homecoming dance. Trent sets up a gym in the garage. Liz and Brice hear hard truths about their house search. Trent and Amber reveal an exciting upcoming trip.

Trent and Amber take Alex and Emma on a trip to Finland to visit their former exchange student, Joose, and his family. Back at home, Liz and Brice are packing up to move in together, and Jonah throws a party as he has the house to himself.

In Finland, Trent, Amber, Emma and Alex head to Elf school before meeting the most famous man of the North Pole. Back at home, Ashley is in town, and Jonah throws a party while Elizabeth plans her 21st birthday.

After Trent weighs in and is surprised by his results, he sees a nutritionist and receives alarming news. Alex and Allie celebrate their four-month anniversary, and the siblings ask about a special milestone. Then, the family hosts a spooky haunted house.

While Trent continues his health and fitness journey, Emma hosts a pop-up shop for her business. Now that Liz and Brice are living together, Trent checks in on how things are going. Then, the family celebrates Thanksgiving with gratitude.

It's Liz's 21st birthday, and the family throws her a hoedown. After surprising news from the nutritionist, Trent must take a P. test. Anna gives an update on her therapy journey. Then, the Johnstons celebrate Christmas.

The Johnstons come together on the court for a game of basketball. Trent and Amber celebrate Trent's weight loss with a boudoir photo shoot. Elizabeth has a heart-to-heart with Amber about her relationship with Brice.