Note: Efa is the mother of Gruffudd ap Rhys according to Ralph A. Griffiths. Sir Rhys ap Thomas and his Family: A Study in the Wars of the Roses and Early Tudor Politics. Cardiff: University of Wales Press, 1993. The ODNB lists Jenet Mathew as Gruffud's mother.
Note: Union began in early 1480s. According to the ODNB, Jenet is the mother of Gruffudd ap Rhys. Efa ap Gwilym is Gruffudd's mother according to Ralph A. Griffiths. Sir Rhys ap Thomas and his Family: A Study in the Wars of the Roses and Early Tudor Politics. Cardiff: University of Wales Press, 1993.