Partners in Crime : Part 1 bbc1

The Secret Adversary - Part One New series. Part one of three. Crime drama based on novels by Agatha Christie. It's 1952, and following a chance encounter on a return train from Paris, ordinary married couple Tommy and Tuppence Beresford are thrust into a world of international espionage. Starring David Walliams and Jessica Raine, with Clarke Peters, Alice Krige and James Fleet

So she has a shilling bet on the favourite in the 12.30 at Catford , and when it wins , gets paid out with a pound note and some silver.
Must be the biggest price favourite ever

30 dog race all joint favourites?

There's always a simple answer staring you in the face.