Estelle Cole
From Tardis Wiki, the free Doctor Who reference
Estelle Cole was a woman who had known Jack Harkness during the War. When she later met Jack again in the 21st Century, she believed that he was the son of the Jack she knew. Jack loved her when she was young and old, they made a vow that they would be together till they died.
While walking through Roundstone Woods she encountered the Fairies after spending her life looking for them. However, she saw them as good, friendly creatures, and never realised their true nature until they killed her by invoking a heavy storm above her, upseting Jack greatly.(TW: Small Worlds)