Imogen Stubbs

 (born 20 February 1961 ) voiced several characters for Big Finish Productions, notably Professor Patricia McBride in The Sixth Doctor Adventures audio series.

Personal Life
She is a second cousin of Mr Smith actor Alexander Armstrong.

The Sixth Doctor Adventures
As Professor Patricia McBride
 * Purity Undreamed
 * The Mindless Ones
 * Reverse Engineering
 * Chronomancer

The Diary of River Song

 * I Went to a Marvelous Party - Isabella Clerkwell
 * The Rulers of the Universe - Isabella Clerkwell