Harriet Vane was born in 1900 or 1903, depending on novel. She could well have still been alive in 1994-98 and thus able to appear on Caroline Aherne's Mrs Merton Show. Thus is engendered one of the world's shortest crossover fics.
"What first, Harriet, attracted you to the millionaire Lord Peter Wimsey?"
For the uninitiated, the reference can be seen here.