Jassy by Norah Lofts

Jassy is about a very unusual girl who might have been born a witch. Its a real love story about how a neighbor saves her from wicked children who want to hurt her because she is different and unlike most she never forgets and helps him to achieve his dream by her efforts. She arranges it so he gets everything that he thinks he wants.
--
'Roughly a third of this novel, about a young English girl who, herself innocent, brings tragedy on everyone, is lesbian in emphasis. In a girl’s school she comes between Mrs. Twysdale, a rather slimy, neurotic woman who has adored her boyish cousin, Katherine, for years. Katherine, chafing at this adoration, turns to Jassy for undemanding friendship and Mrs, Twysdale connives to have her expelled—which spurs Katherine to precipitate a long-desired break with her.' ~ Marion Zimmer Bradley