Mrs Wotherspoon

In the novel A Murder is Announced, Miss Marple mentioned Mrs Wotherspoon. She drew her own and Mrs Bartlett's Old Age Pension, although Mrs Bartlett had been dead for years. Miss Marple mentioned this to make the point that one old lady is very like another.

Later on, Miss Marple was able to deduce that Charlotte Blacklock had assumed the identity of her sister, Letitia, and was able to do so without anyone noticing because one old lady is very like another.