 Drinkwater is the daughter of the bandleader and agent, Peter Regan (born Peter Albert Drinkwater) and Irish nurse, Phillis McCormack; her sister is actress Linda Regan.She was a member of the National Theatre Company under the leadership of Laurence Olivier and has acted in numerous television series and films including the highly successful "Chocky", "Bouquet of Barbed Wire", "Another Bouquet" and "Golden Pennies".Drinkwater won a Critics' Circle Best Screen Actress award for her role, Anne, in the feature film "Father" (1990) in which she starred opposite Max von Sydow.