Kristin was born in Kent to an English father and Norwegian mother and her childhood was spent shuttling between both countries.

After university at UEA, she trained at RADA, where her contemporaries were Trevor Eve and Alan Rickman. Her first job was in rep in Manchester, where she joined forces with Rickman and Belinda Lang at the Library Theatre. This was followed by nine months at the Crucible Theatre, Sheffield, where again she worked with him in two plays - Ibsen's When We Dead Awaken and Nijinsky.

At Leicester she played Portia in The Merchant of Venice, before moving to the National Theatre. She was in the Royal Shakespeare Company's celebrated production of Les Liaisons Dangereuses, with Rickman as Valmont. She's perhaps best known for her Petra in The Bitter Tears of Petra von Kant and for Helen in The Women of Troy. Kristin was a finalist in the Off West End Awards 2019 for playing Marcie in Halley Feiffer's play A Funny Thing Happened......