Isabel de Ros Peerage person ID=402750 (d. 1309) Parents Eustache FitzHugh Sir William de Ros Children Katharine Thweng William de Thweng, 2nd Lord Thweng Lucy de Thweng Marmaduke de Thweng Robert de Thweng, 3rd Lord Thweng Thomas Thweng, 4th Lord Thweng Siblings Ivette|Juette de Ros Lucy de Ros Partners Marmaduke Thweng, 1st Baron Thweng