She was first mentioned in Beck and the Great Berry Battle, when they say that a raccoon had trampled through her garden.
In Tinker Bell to the Rescue
Thistle is jealous of Tinker Bell, because Thistle has a crush on Terence Terence. Thistle plots against Tink several times, such as making others think she had lost her talent by ruining one of her pots, turning her into a bat by making her listen to a Mermaid sing, and putting quarrelweed in Bess's studio knowing that Tink was going to stop by with Terence. Thistle really feels bad about this, that's when she meets Jerome and starts to develop feelings for him. He pushes her to apologize to Tinker Bell, but she doesn't know how Tink forgives her, when she sees her crying. She becomes friends again with everyone.