Mrs. Krum is the mother Viktor Krum. She is a Bulgarian woman who is described as having dark hair.[1]
Mrs. Krum travelled to Hogwarts School of Witchcraft and Wizardry with her husband to watch Viktor face the final task of the Triwizard Tournament in 1994.
Her son told Harry Potter that his grandfather was murdered by Gellert Grindelwald.[2] It is possible that this man was either Mrs. Krum's father or her father-in-law.