Is Kristine Sutherland related to Kiefer Sutherland?

No, Kristine Sutherland is not related to Kiefer Sutherland or Donald Sutherland (his dad).

She was born Kristine Young and she changed her name because she was being confused with another similarly-named actress. She chose Sutherland because she had named her pet cat (Donald) after Donald Sutherland.