Ithel Fychan, lord of Mostyn

Parents

• Rhys Fychan ap Rhys Mechyll ap Rhys Grûg ap Lord Rhys of Dinefwr, aka Rhys Ieuanc
• Gwladus ferch Gruffudd ap Llywelyn

Children

• Margred ferch Llywelyn ap Dafydd Dinlaes ap Dafydd of Tegeingl cantref

Siblings

• Margaret ferch Rhys Ieunac
• NN ferch Rhys Ieuanc ap Rhys Mechyll
• Margred (2) ferch Rhys Ieuanc ap Rhys Mechyll ap Rhys Gryg