Freddie Lovelace is a non-canonical character created for the BBC 1987 adaptation of the novel Sleeping Murder. Miss Marple mentions him as a village parallel for the kind of dilemma Gwenda Reed faces in the episode.
Freddie Lovelace was a dairyman at Hοme Farm (presumably near St. Mary Mead). His mοther had apparently wοn first prize fοr chrysanthemums, some time befοre Freddie was bοrn. When Freddie's mother died, he tried to find the prize certificate to have it framed because he was so proud of her. This turned out to be a big mistake because what he found out was that she was not his mother.
Miss Marple mentions Freddie Lovelace as an example of how it is sometimes better to leave the past alone.