John Ferrier was walking through the wilderness of the Great Alkali Plain carrying a little girl, they were the last two of a party of 21 people looking for a better place to live. Like the others, the elements began to get the better of him, but to his surprise he was rescued by a group from Nauvoo, Illinois. (A Study in Scarlet)

 

Cared for by John Ferrier after her mother died. She married Drebber and so the case of A Study in Scarlet began!

 

Mary Morstan's employer who once consulted Holmes on a 'little domestic complication'. (The Sign of Four)