In the novel The A.B.C. Murders, The Ginger Cat is a tea room in Bexhill-on-Sea. Miss Merrion is the proprietor, and Betty Barnard worked there as a part time waitress. One of the other waitresses there is a girl named Milly Higley.
There are actually two Ginger Cat cafes in Christie's stories. The proprietress is not always mentioned so it is not known if all of them had ginger-coloured hair.