In the short story The Unexpected Guest (later, chapter 1 and 2 of The Big Four), Mrs Pearson was Poirot's landlady. Her property was at 14 Farraway Street, Hastings also describes her as "my old landlady", suggesting that he had also been her tenant. Dr Ridgeway, who had a practice a few doors away, referred to her as "Mrs Funnyface".
She makes another appearance in The Baited Trap, (later, chapters 12 and 13).