She is a caretaker who looks after other Pokémon. She found a wounded Turtwig and took care of it. In Gettin' Twiggy With It!, she gave Ash his Turtwig.
Turtwig acted as the wild Pokémon that lived around Clara's area's protector, and challenged Ash and Pikachu when they came. However, they defeated Turtwig, but it was still resentful. However, after Ash and Pikachu save the local Pokémon from Team Rocket, Turtwig loses his resentment for Ash and challenged him to a battle once more, as he wanted to be captured fairly and go with Ash on his journey. Clara allowed this and Ash defeated and captured Turtwig, bringing it along with him on his adventure.