Agnes de Ferrers Peerage person ID=158520 (b. 1250) Parents William de Ferrers, 5th Earl of Derby Margaret de Quincy, Countess of Derby Children Hawise Muscegros Siblings Joan de Ferrers Alianore de Ferrers Elizabeth Ferrers Robert de Ferrers, 6th Earl of Derby Isabel Ferrers Agatha Ferrers Sibyl de Ferrers William Ferrers Maud Ferrers Joan de Ferrers Agnes Ferrers Partners Robert de Muscegros John FitzReginald