Who is Adelaide Veen from Ada; or, Ardor: A Family Chronicle and what is their importance?

Adelaide Veen is Marina and Walter D. Veen's daughter. She was born on July 21, 1872, and lives at Ardis Hall with her parents and sister, Lucette. Adelaide and Van fall in love when she is twelve-years-old. They are then separated for four years while Adelaide attends boarding school, and although, Van initially waits for Adelaide..... the waiting ends when he learns she's taken other lovers. In the end, the couple finds their love would have been forbidden regardless, as they are actually bother and sister. Adelaide goes onto become an actress and photographer.