I'm reporting you two for madness
Penny Carter was a journalist, working as science correspondent for The Observer. She attended a press conference at Adipose Industries. She was very sceptical about the diet pill, and decided to investigate it a bit further. She stayed at Adipose Industries till after closing time, hidden in a toilet stall. She was discovered by Miss Foster, thus saving Donna who was hiding in a stall near by.
Miss Foster took Penny to an office, and her security men tied her into a chair. She was later saved by the Doctor. (DW: Partners in Crime)
Behind the Scenes
Before Catherine Tate agreed to reprise her role as Donna Noble, Russell T. Davies wrote a character called Penny Carter to be the Doctor's companion. This character was scrapped when Tate agreed to appear as Donna. Penny Carter was later used as the name of an investigative journalist who was investigating Adipose Industries. (DW: Partners in Crime).