In Valentine's Day, Isabelle is part of the featured character display in the Residential Services section of the Museum. In the game, Isabelle is once again the mayor's assistant, but now her voice is recorded in a message for the player's Valentine. She is also mentioned by name in the game, appearing as one of the main characters present in Lyla's flashback where she and Lyla told the player about how they met, and it is also revealed that she was head of the Nook's Island office before Brenda replaced her.
In Cradle of Hope, Isabelle is played by the same actress, Melissa Villaseñor, as in Valentine's Day, and is once again the mayor's assistant. Unlike the previous Isabelle, Lyla is her counterpart in this game, and the two occasionally interact.
Isabelle in the Nook's Island Series
Isabelle was created to fill the void of a small town mayor that Tom Nook was unable to create, giving him a small role in New Leaf and being Lyla's assistant in Valentine's Day. Nook's Cradle of Hope reveals that she, and her two fellow villagers, have reached adulthood, and that they would like to move out of the Nook's Island, having lived there since birth.
The Isabelle appearing in Valentine's Day has a completely different personality than the one from New Leaf and Nook's Cradle of Hope. The Isabelle in Valentine's Day 827ec27edc