The role was announced by Big Finish at their convention taking place in Barking today; recording for her adventures commenced last week, with three tales expected to be released from January 2012. Their website has since been updated about the news, with executive producer Nick Briggs saying:
We worked with Lisa for one day on The Crimes of Thomas Brewster, and line producer David Richardson and I were of the same mind. She was great, and she'd make a perfect companion. Flip is young, brave, fun but she has a lot to learn - and the Doctor takes on something of a Professor Higgins role in her life.
On television, Greenwood is to be a series regular in the forthcoming Kudos series for the BBC, The Hour, and has previously appeared in Doctors, The Bill, and Silent Witness.
(with thanks to Richard Brinck-Johnsen)