Sarah Jane Smith.

About Sarah Jane Smith

Sarah Jane Smith is a fictional character played by Elisabeth Sladen in the long-running BBC television series Doctor Who and two of its televised spin-offs. Sarah Jane is a dogged investigative journalist who encounters the Doctor, an alien time traveller, and becomes his travelling companion on a series of adventures throughout space and time. After parting ways with the Doctor, she continues working as a journalist, uncovering sinister developments on Earth, and defending the planet from alien invasions alongside her neighbours. She occasionally reunites with the Doctor during her own adventures.