Doctor Who Speculation

So, while waiting for a Doctor Who panel at AwesomeCon I decided to check and see if anything more had announced or leaked about the new series.

The biggest news is that Sharon D Clarke has shared something about her "returning" role. (Meaning she's playing somebody we've seen before).

I was speculating that she might actually be the Master, but it appears that isn't true. Unless she's lying (always possible with anyone associated with Dr Who), Clarke's character will be human and married to Companion Graham (played by Bradley Walsh). This makes it possible that Ryan (played by Toisin Cole) is, in fact, Graham's son - a fascinating dynamic I'd love to see.

So, if this is true, then who is Sharon D Clarke playing?

Could she be an older Martha Jones? This seems unlikely...but possible. I'm going to make a case for her actually being an older Courtney Woods - the student who was a Companion for precisely two episodes in series 8. The Doctor, who apparently doesn't know the rule, does say that Woods will become "President of the United States" - definitely unlikely, but we all know that the Doctor lies.

So, what do people think? Martha or Courtney? (There's nobody else I can think of that she could be). If she's Courtney then that pushes the timeline for Graham's origins a bit into the future, which would be nice.

Or Clarke is following the grand tradition of releasing disinformation and it's something else altogether. Maybe she's Romana...