This was a breakthrough for Isabelle's development as she was not only included in Mario Kart 8 but brought back a second time for the Switch version over older main characters of Animal Crossing such as Tom Nook. Isabelle's first big breakout from the Animal Crossing Series was being included as a main playable character in Mario Kart 8. Originally included as part of the Animal Crossing x Mario Kart 8 DLC, both her and two Villagers are included to race. She mainly uses the City Tripper bike, and her stats in the Switch version are compatible with the likes of Toadette and Wendy. Crafting Isabelle's Slideshow will personally invite her to the player's campsite.

In Pocket Camp, she encourages players to make the most out of their campsite by offering tips and providing various goals to achieve. In Home Designer, her role is very similar to New Leaf, where she gives the player Public Facility projects and, by scanning her Amiibo Card, she will have her own home built that she shares with Digby. Isabelle also makes appearances in the smaller Animal Crossing releases, Happy Home Designer and Pocket Camp. She was also granted the role of reminding the player about saving their game until the Reset Center is built, temporarily replacing Mr. Isabelle can mostly be found in New Leaf in the town hall but is the main character to assist with ceremonies and will stand in the plaza during events. Her twin brother Digby is also introduced in the game but has a smaller role as the owner of the Happy Home Showcase. In New Leaf, players first meet Isabelle at the start of the game, where she helps the player move in by offering advice and optional tasks like Tom Nook would have in previous games.

Isabelle animal crossing