Passage: In 1973, Doctor Who actress Katy Manning, who was playing the Third Doctor's assistant Jo Grant opposite Jon Pertwee, was leaving the series; Z-Cars producer Ron Craddock gave Sladen an enthusiastic recommendation to Doctor Who producer Barry Letts. Sladen arrived at the audition not knowing it was for the new companion role, and was amazed at Letts's thoroughness. She was introduced to Pertwee, whom she found intimidating at the time. As she chatted with Letts and Pertwee, each time she turned to look at one of them the other would signal a thumbs-up. The role of Sarah Jane Smith was originally given to comic actress April Walker, but allegedly during rehearsals for debut story The Time Warrior, doubts over the pairing of Walker and Pertwee surfaced and the part was re-cast to Sladen.She stayed on Doctor Who for three-and-a-half seasons, alongside Pertwee as the Third Doctor and Tom Baker as the Fourth. She returned to the character of Sarah Jane Smith on several later occasions. In 1981, new Doctor Who producer John Nathan-Turner asked her to return to the series to ease the transition between Tom Baker and new Doctor Peter Davison. She declined but accepted his second offer of doing a pilot for a spin-off series called K-9 and Company, co-starring K-9, the robot dog from Doctor Who. However, the pilot was not picked up for a series. Two years later Sladen appeared in the 20th anniversary special The Five Doctors.She reprised the role in the 1993 Children in Need special Dimensions in Time, and in the 1995 independently produced video Downtime alongside former co-star Nicholas Courtney as Brigadier Lethbridge-Stewart and Deborah Watling as Victoria Waterfield. This was her last on-screen appearance as Sarah Jane Smith for some time.

Question: What is the characters name?
Sarah Jane Smith