From the Super Mario Wiki
In Mario & Luigi: Partners in Time, Toadiko accompains Peach on her visit to the Mushroom Kingdom of the past in Professor E. Gadd's time machine. Unfortunately, Toadiko, Peach and Toadbert visit during the Shroob invasion of the kingdom and are captured by the Shroobs. When the princess is captured by Princess Shroob, Toadiko and Toadbert both escape but separate at some point due to unknown reasons. While Peach is imprisoned, Toadiko is sent to Toadwood Forest and strapped to a vim-draining tree. When the Mario bros. of past and present arrive in the forest, they discover Toadiko's near-lifeless body. With much of her vim drained, Toadiko has very little stamina left. She manages to reveal to the four Mario brothers that the Shroobs have captured Peach, and they are draining the vim from Toads to use as fuel for their flying saucers.
The Shroobs overhear the conversation. As such, a Shroob UFO arrives and shoots an energy blast at Toadiko, turning her into a Shroob Mushroom. Toadiko's last words to the Mario brothers are "Gather... shards...", referring to Cobalt Star shards. When E. Gadd uses the Hydrogush to send the baby tears into the past to destroy all Shroobs, she is turned back to normal.