In the Land of Stories series, she briefly appears in Beyond the Kingdoms.
Appearance and Personality
She is described as a pretty young woman wearing a purple veil. She lives in Nottingham Castle.
She initially does not like Robin Hood, because of his loud voice and narcissistic manner, and actively avoids him when he comes to call. When Robin follows Conner's advice and lowers his voice and compliments her, she is much more receptive of his advances.
The Sheriff of Nottingham is also in love with her, and is feeling very resentful that she doesn't love him in return despite giving her a place to stay in the castle, and gifts of nice dresses and veils. He says she treats him like he is her captor. 
After Robin has won her love, Marion's lock and key are used as components of The Portal Potion created by Conner in Sherwood Forest.