How to Unlock Rosalina
Rosalina is an unlockable character in Super Mario 3D World + Bowser’s Fury. You need to progress significantly through the game (World 9) to make her playable.
Clear World 9-2
Rosalina is unlocked by clearing World 9-2 (Star World – Super Galaxy). She will appear when you reach the area with the flagpole.
Rosalina can perform a special spin attack that can act as a double jump when used in midair. This can be useful for reaching high areas or attacking flying enemies. Rosalina, however, suffers from having somewhat slower dash speed compared to other characters.