- Parents operated a tavern in Coleraine, Northern Ireland.
- Got her start in drama with the Ulster Youth Theatre.
- Made London stage debut in 1986.
- Played the killer in the Inspector Morse puzzler The Way Through the Woods, which aired on PBS's Mystery! in 1997.
- Made Broadway debut in The Weir in 1999.
- Earned a 2008 supporting-actress nomination for an Olivier (the British equivalent of the Tony Awards) for her role as Emilia in Othello.
- Played Hermione Granger's mother in Harry Potter and the Deathly Hollows (Parts 1 and 2).