Toadette is a member of the Toad species that appears as a playable character in various spin-off games. She appears to be the female version of a "Toad" or "Mushroom Person". Toadette is first introduced in Mario Kart: Double Dash!! as the partner of Toad. she was then shown in Mario Party 6 as an unlockable character. In other games, she simply acts as an instructor or a background character, for example in Paper Mario: The Thousand-Year Door (in which she apparently has feelings for Mario, even becoming tearful at the end of her last session with him). She has a cameo alongside Toad in the intro of Super Mario Galaxy. Jen Taylor is her voice actor in the main series and Jennifer Hale takes up the role in Dance Dance Revolution: Mario Mix. Recently, in Mario Party 8, she was voiced by Nicole Mills. She also appears in Mario Super Sluggers as a playable character for the Peach Monarchs.
In Super Smash Bros.
She also appears as a trophy in Super Smash Bros. Brawl.
Mario Party DS
In Mario Party DS, Toadette is one of the five board owners who begs for Mini Mario's help. In the game, a rogue Hammer Bro. is destroying all of her instruments in search for the rare star piece. When Mario and gang destroy the Hammer Bro., Toadette thanked them by giving then the second Star piece.
Paper Mario: The Thousand Year Door
In Paper Mario: The Thousand Year Door she taught Mario how to use abilities that he finds in certain treasure chests. She was sad that she wouldn't see Mario again after the last chest.
Mario Power Tennis
Toadette appears in the intro of Mario Power Tennis as on the board it shows Toad and Toadette on the board but they never became playable in the game. Maybe the creators were going to make her playable but decided not to and never changed the intro.
Mario Kart Wii
Toadette appears as an unlockable light weight character in Mario Kart Wii she is unlocked by having a time set on all the courses in Time trials.
Mario Party Series
Toadette made her first Mario Party appearance as an unlockable character in Mario Party 6. She was default for numbers 7 and 8, but made a non-playable appearance in Mario Party DS.