Jasmine is the Gym Leader of the Olivine Gym and she also runs the Glitter Lighthouse in Olivine City where her Ampharos is stationed. She first met Ash and his friends at the lighthouse when her Ampharos was sick. Ash went and got some medicine for it.
At a later time, Ash challenged Jasmine for a gym badge. Ash's Pikachu and Cyndaquil battled against her and proved to be a sufficient combo in order to defeat her and obtain the Mineral Badge.
Jasmine met up with Ash and Brock in Sunyshore City in the Sinnoh region. She met Dawn and the Sinnoh Elite Four member Flint. She challenged him to a battle with her Steelix but Flint used his Infernape which had a significant type advantage as well as being his most powerful Pokémon. Jasmine was easily defeated by Flint.