Walda Bolton

Walda Frey is an unseen character in the third season. She is the new wife of Roose Bolton, the Lord of the Dreadfort.

Season 3
During the wedding feast of Edmure Tully and Roslin Frey, Lord Bolton recounts to Catelyn Stark and Ser Brynden Tully how Lord Walder Frey proposed him to marry one of his daughters or granddaughters and offered her weight in silver as dowry. Lord Bolton then adds he chose the fattest bride available.

In the books
In the A Song of Ice and Fire novels, Fat Walda is the second of three daughters of Merret Frey, himself the ninth son of Lord Walder.