Kate Fleetwood has been cast in Harry Potter and the Deathly Hallows as Mary Cattermole, who is Reg Cattermole’s (who will be played by Steffan Rhodri) wife. [spoiler] Reg is the wizard Ron turns into when the trio breaks into the Ministry and Harry saves Mary when she has a hearing in front of Umbridge.[/spoiler]

Thanks SnitchSeeker!