Chinhilda is Grimbeard's wife, and Hiccup's great great grandmother.
Chinhilda was a proud Viking woman. She loved all of her children dearly. Especially, her youngest, Hiccup II. However, the Naming Dame considered Hiccup II a runt. Thus Grimbeard stole Hiccup II from Chinhilda while she slept, and left him on the mountainside to die. When Chinhilda found out, she was furious, and attacked him. He defeated her and exiled her. She placed a curse on the Tribe, and spent the rest of her life searching in a white boat for Hiccup II. She is now the Ghost of the Bay of Broken Hearts.
She was described as having blonde hair and blue eyes, this trait was passed down to Hiccup II.
Snotlout describes her as a terrifying woman of pale white light, who would reach out and rip out the hearts of Vikings.