A cynical person might call Dickon Sowerby one of Mary and Colin's token financially poor, morally rich friends. Two years older than Mary and Colin, Dickon works at the Craven's manor and is very outdoorsy and beloved by animals. Skylan Brooks was excellent in George Tillman Jr.'s The Inevitable Defeat of Mister and Pete, and we think he'd make an excellent Dickon.
Colin Craven is Mary's wheelchair-bound (or, initially wheelchair-bound) cousin, whose widowed father has taken Mary in. Like Mary, Colin is neglected by his parent. Mary takes pity on her cousin, they become friends, and both are changed for the better. We nominate Tyrel Jackson Williams, the younger brother of Everybody Hate's Chris' Tyler James Williams, to play Colin.
Mrs. Medford is the Cravens' housekeeper and the primary caretaker of Colin and Mary. In the 1993 version, Dame Maggie Smith played Mrs. Medford. We'd like the slightly younger acting powerhouse, Alfre Woodard, to play Mrs. Medford.
Mary's uncle, Archibald Craven, is really the husband of her father's sister, who passed away many years ago. Never the same since his wife's death, Archibald is absently moping for most of the book. We would like Forest Whitaker to play Archibald Craven.
Martha Sowerby is Dickon's sister and Mary's maidservant-turned-BFF. We think the sweet little (but older than Quvenzhané) girl from The Hunger Games, Amandla Stenberg, could make a good Martha.
For most of the book, Mary Lennox is 10 years old, and everyone knows that the best actress in the 10-to-13 range is Oscar nominee Quvenzhané Wallis. Wallis is not, strictly speaking, of the same nationality or race as Burnett's protagonist, but we're hoping that Del Toro et al. will update the setting and bring Burnett's beloved book into the 21st century. If we wanted to watch a stuffy film about the Yorkshire moors, we'd rent Wuthering Heights.