Every Susan Twist Appearance in Doctor Who So Far (There's always a Twist at the end) 

an updated video before season 1 finale... how many more Susan's are gonna appear in this season??

She’s Stan Lee. He regenerated

‘73 Yards’: She was the hiker that Ruby spoke to after leaving the clifftop. ‘Dot and bubble’: She was “Mummy”.

And now she's the hiker ruby meets in 73 yards

Reminds me of Clara going throughout the Doctors timeline

I reckon she'll be Ruby's mother or The One Who Waits. Maybe even both!

I think she’ll be a nod to Clara who got reincarnated in different timelines. The Doctor doesn’t recognize her face anymore. Ruby’s ‘mystery’ will be something new and none of us saw coming like Clara’s part!

She’s also the portrait in rogue

Why is she appearing in every episode it seems like she is teleporting wherever the doctor goes

Interesting theory. There’s a chance she could be Suzan (Doctor’s granddaughter, due to Devil’s Chord), while also being Ruby’s mother / creator (since baby farms were introduced in ep.1)) & the ‘One who waits’.

She appeared in Dot and Bubble as well

On the next episode she is names S Triad. With a technology firm. S TRIAD...TARDIS obviously, she is a timelord...im thinking the new master. Who else has a tardis ?

The first face we see starting this series

I don't think she's Ruby's mother or the new mistress?

are you going to do another update

Has anyone ever thought that it could be a future Rose Tyler who figured out how to reopen the barriers to the Parallel Worlds?

Could ruby be doctor biological great granddaughter via Susan?