Jacquetta of Luxembourg, Countess Rivers (1416-1472) mother of Elizabeth Woodville aka: "The White Queen." She was an influential figure in the War of the Roses and was accused of witchcraft although it was never proven. She was also invested as a Lady Companion, Order of the Garter (L.G.) in 1435. My 18th GGM.
RED ROSE~~ Katherine of Valois was a wife of Henry V, mother of Henry VI. Later she was wed with Owen Tudor and became mother to Edmund, Jasper, Margaret, Catherine and Tasinda Tudor. So she was a paternal grandmother of Henry VII
Owen Tudor (d. 1461) was a soldier and courtier, descended from a daughter of the Welsh prince Rhys ap Gruffudd, "Lord Rhys". However, he is particularly remembered for his role in founding England's Tudor dynasty. (15th Great Grandfather)
ELIZABETH OF YORK What the keen eyed of you will notice is that the York(white rose) Princess is holding a Red rose (for Lancaster) thus we can infer that it is after her marriage and well into the tudor reign.