The relationship begins as protective control and ends when Rapunzel rejects the Witch.
Rapunzel is explicitly described as the Witch's adopted daughter, and the Witch keeps her isolated in a tower.
Their shared family history connects the Baker's curse to the Witch's past actions.
The plot states that Rapunzel is the Witch's adopted daughter and the Baker's biological sister.
Explore the full interactive character relationship map of Into the Woods