Elisabeth Sladen (in-universe)

In an alternate dimension, Elisabeth Sladen was an actress who portrayed Sarah Jane Smith in the television series, Doctor Who. She died at some point before 2013; when the Eleventh Doctor found out about this, he revealed that the Sarah Jane in his universe was still alive and well. (COMIC: The Girl Who Loved Doctor Who)

Behind the scenes
Though not mentioned in the comic, Elisabeth Sladen was in The Android Invasion. The real world serial, TV: The Android Invasion, starred Sladen as Sarah Jane and Tom Baker as the Fourth Doctor.