She appeared in episode 7 of the Pokemon Indigo League Series. She is the first Officer Jenny who Brock was hitting on. Her sister in law is the Officer Jenny of Viridian City. She accused Ash Ketchum of being involved in the theft.
Excited about winning his Boulder Badge, Ash is extremely excited to get to Cerulean City to battle for his Cascade Badge. For some reason, though, Misty seems to be trying to avoid entering Cerulean, and tries, unsuccessfully, to convince the others to go to Vermilion City instead. She leaves Ash and Brock as they enter the city. When Ash and Brock enter Cerulean City, they see a big crowd of people in a circle surrounding a building. When they get to the front, they see Officer Jenny, and she accuses Ash and Brock of being criminals. When they prove their innocence, she lets them go, and sends the rest of the crowd away. After that, they sit on a bench and Ash asks Brock for inside information on the Gym Leader. Brock tells him that as a Gym Leader, he cannot give out that information. Then Brock decides to check something out that he has been meaning to look at. They split up, and Ash heads to the Cerulean Gym alone. When Ash reaches the Gym, he finds three sisters performing an underwater show for a crowd of people. Ash meets the girls backstage, finds out that they are the Gym Leaders, and challenges them to a battle. The girls, Lily, Daisy, and Violet, explain that their Pokémon are too tired to battle, and offer to give Ash the Cascade Badge without a proper match. Misty, who has been spying on the entire scene, interferes at the last minute and challenges Ash to a battle. As it turns out, Misty is herself a Cerulean Gym Leader as well, and also the youngest of The Sensational Sisters, but because she is so much younger than her three sisters, they call her a runt and refuse to acknowledge her as being just as good as they are. After Misty argues with her sisters, she challenges Ash to an official Cerulean Gym battle, two Pokémon per side. Ash tries to send out Pikachu, but Pikachu refuses to go into battle because he does not want to hurt Misty or her Pokémon. Instead, Ash sends out Butterfree to battle Misty's Staryu. After a quick battle, Butterfree gets knocked into the water, causing it to lose the battle. After that, Misty sends out Starmie and Ash sends out Pidgeotto. Pidgeotto uses Whirlwind on Starmie, but it jumps into the water and attacks Pidgeotto. Pidgeotto uses Gust, causing Starmie to hit the wall. Just as Ash is about to win the battle, Team Rocket interrupts and tries to steal all of the Water-type Pokémon and the water from the Gym using a giant vacuum machine. While Team Rocket's vacuum is sucking up the Water Pokémon, it sucks in Pikachu as well. He releases a Thunderbolt attack, which explodes the machine, sending Team Rocket flying. After Team Rocket is gone, Daisy gives Ash the Cascade Badge. Misty tries to argue, but her sisters convince her that if Ash had used Pikachu from the start, he would have easily beaten all of her Water-type Pokémon. Misty agrees with her sisters and claims that when she comes back from her journey with Ash, she will be a great Trainer. Brock then meets Ash outside of the Gym, and together they all head for Vermilion City.