From their marriage was born the Roger Mortimer who was lord lieutenant of Ireland, during a part of King Richard's reign, and was killed in the wars of that country.

He left two sons, of whom the elder was but eight or nine years old, when Richard was dethroned; and he and his brother are now living at Windsor, and are well treated there by the king.
"Had my lord's nephew attained the age of manhood, at the deposition of Richard, many would doubtless have supported his right to the throne; but for a child of eight to rule this realm, and keep in check the turbulence of the great lords, would be so absurd that no one even mentioned his name; and Henry, of course, ascended the throne as if by right of conquest." "I have heard something of this before, Sir John; but as the Percys were among the chief supporters of Henry, the fact that there was one who had greater rights to the throne was never talked of, at Alnwick; although, by Percy's marriage with Sir Edmund's sister, he became uncle of the young Earl of March." "I can understand that, and indeed Sir Edmund himself has never, in the most intimate conversation with us, expressed any opinion that the young earl would, if he had his rights, be King of England.".