Katrina Umber

Katrina Umber, née Cerwyn, is an unseen character in Game of Thrones. She is not expected to appear in the series, being long dead by the time it starts.

Background
Katrina was born to Cleos Umber and Vivian Cerwyn and married Joseth Umber, with whom she had two children.

Season 1
She is mentioned in The Lineages and Histories of the Great Houses of the Seven Kingdoms.

Reference

 * "A Golden Crown"