Jacqueline King
From Tardis Wiki, the free Doctor Who reference
Jacqueline King played Sylvia Noble in Doctor Who beginning with the 2007 Christmas special The Runaway Bride. During Series 4, she made several appearances as Sylvia, and returned to the role again in 2009 for the final David Tennant storyline, The End of Time.
She also played "Barbara" in the Big Finish - Doctor Who Unbound production Deadline.