Who is Maude Clifford from The Reckoning and what is their importance?

Maude Clifford is the granddaughter of Llewelyn Farr, cousin to both Llewelyn ap Gruffydd and Ellen de Montfort. Widowed at a young age, she is then kidnapped by the ruthless John Giffard who seeks to claim the lands of her dead husband. She is raped and forced into marriage by Clifford who locates a priest willing to overlook the obvious coercion for a price. Her pleas to the English King for help go unheeded, and once she is pregnant, she gives up hope for escape.