Played by Britishactress Elisabeth Sladen, who costarred with Jon Pertwee as the Third Doctor from 1973-1974, and Tom Baker as the Fourth Doctor from 1974-1976, Lis has also appeared as Sarah Jane in "K9 & Company" in 1981, and alongside David Tennant as the 10th Doctor in the Doctor Who episode "School Reunion" in 2006.
Because Lis has aged more gracefully than a Time Lord, Sarah Jane has turned into such a MILF - even though she's old enough to be a GILF - that (a) David Tennant totally broke character and turned into a masturbatingfanboy in all of his scenes with Lis, and (b) Sarah Jane's adopted teenage son on "The Sarah Jane Adventures" is doomed to develop an incurable Oedipus complex because of her.
"Wow, you managed to break into Torchwood's secure files? You're a real Sarah Jane!"
"Don't get me wrong, Jackie Tyler is one fine asschav, but she's no Sarah Jane."