Origin
Angela Stover, A.K.A. Winter Woman, was one of many heroes who joined the Anti-Registration Underground. It is unknown as to whether or not she was arrested by S.H.I.E.L.D. when they discovered the location of the Underground.
Creation
Winter Woman was created by Paul Jenkins and Ramon Bachs, her first (and only) appearance being in Civil War: Front Line #4 – Embedded, Part 4.