Whitney participated in a race against Gold, where she sent Mil Mil to attack him with Rollout. She came to a strange looking tree and tried to have her Mil Mil use Tackle on it. However, the tree took no damage. Soon enough, a Rhydon appeared and hit Mil Mil, then captured Whitney.
Mil Mil helped Whitney descend down to Mahogany Town's Gym. There, she and the radio crew came to interview the town's Gym Leader. However, Whitney accidentally slided down the icy floor, so her Mil Mil stomped on the ice, preventing her and others from crashing. After meeting up with Pryce, the group faced a Suicune, so Whitney had her Mil Mil battle it with Rollout. Just as Whitney became happy Suicune was defeated, Mil Mil fainted, as Whitney was deceived by Suicune, who defeated her Pokémon. After recalling Mil Mil, Whitney sent it back to take Suicune's Mirror Coat, which reflected Pryce's Swinub's Powder Snow. However, Mil Mil recovered herself with Heal Bell. By using Dynamic Punch, Miltank attacked Suicune, allowing Whitney to catch it, only to be explained the Suicune was an icy statue.
Whitney came to the Indigo Plateau, where she and Miltank participated in the Gym Leaders' tournament. She fought against Misty's Starmie; Miltank used Rollout, but was countered by Starmie's Rapid Spin, followed by Flash. With Hyper Beam, Starmie defeated Miltank, knocking Whitney out of the tournament.
Due to Team Rocket having infiltrated into the Indigo Plateau, Whitney and Miltank battled the grunts. Battling inside the train against Team Rocket forces, Whitney advised the others their Pokémon could recover by drinking Mil Mil's drink, who was also battling the grunts.
|Tackle||How Do You Do, Sudowoodo?|
|Stomp||Irked Igglybuff and Curmudgeonly Cleffa|
|Heal Bell||Savvy Swinub|
|Dynamic Punch||Savvy Swinub|
|Milk Drink||The Last Battle III|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- ^ GS015: Smeargle Smudge
- ^ GS016: How Do You Do, Sudowoodo?
- ^ CR027: Irked Igglybuff and Curmudgeonly Cleffa
- ^ CR028: Savvy Swinub
- ^ CR038: Yikes, It's Yanma!
- ^ CR040: Notorious Noctowl
- ^ CR049: Lugia and Ho-Oh on the Loose (Part 1)
- ^ CR053: The Last Battle III
- ^ HGSS001: Out-Odding Oddish
- ^ HGSS003: One Tough Togepi