Pssst! Guys! We’ve seen this girl twice now – once in Deep Breath, once in Into The Dalek (where she briefly appears in a scene with Danny). And she has a name, Courtney, and she’s played by Ellis George. And, (look away now if you want absolutely no spoilers altogether) here’s something Samuel Anderson Instagrammed a while back:

“there’s a new member in the #whocrew my little sis @ellisgeorge” [x]

We’ve met Danny’s little sister!