Corin Umber

Corin Umber 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. She is one of the earliest recorded members of House Umber, and an ancient ancestor of the Greatjon and of Lord Rickard Karstark.

Background
Corin Karstark is an early member of House Umber.

Season 1
She has an entry in The Lineages and Histories of the Great Houses of the Seven Kingdoms.

In the books
Corin Karstark is referenced only in the TV adaptation of A Song of Ice and Fire and has no corresponding counterpart in the books.