6DoctorWhoDan7 wrote:Given that her character [a real person by the way] is dead pretty unlikely, also he would be crossing his own Time-stream and that's a big No-No.
But when the Doctor went back to see her, she was already dead. It's possible 11 (or some future version of Season 2 Ten) had adventures with her, brought her back the next day, and swore her to never tell anyone, not even his younger self in the letter she would write to 10 before her death. She never saw him; she was not there to "remind" him of what they'd done, when it in fact hadn't happened to him (10) yet.