Ellie Darcey-Alden
From Tardis Wiki, the free Doctor Who reference
Ellie Darcey-Alden portrayed Francesca Latimer in the 2012 Doctor Who Christmas television story The Snowmen.
She is the elder sister of of Joseph Darcey-Alden who portrayed Francesca's brother, Digby Latimer, alongside her.
Before Doctor Who, she also appeared in another famous series: the Harry Potter series, where she played a younger version of Harry's mother in Harry Potter and the Deathly Hallows: Part 2.
