Rachel Elnaugh was the first woman to join the investment panel on the BBC television show Dragon's Den.
Elnaugh was part of the original group of dragons when the British series launched. Her role was significant because she brought the experience of founding and running a consumer business to a panel that initially had a predominantly male lineup.
She was followed by other well-known female dragons, including Deborah Meaden, who joined in the third series, and Kelly Hoppen, who joined much later. This sequence is why the answer is not Meaden, despite Meaden being the longest-serving female dragon most viewers associate with the programme.
Elnaugh's connection with Red Letter Days further distinguishes her from later panel members: she founded that company before becoming a television investor.