In the novel At Bertram's Hotel, Lord Coniston (Surname Blake) was a rich nobleman and the father of Elvira Blake. He died when Elvira was five years old. Upon his death his title and the estate would go to a cousin, but since he didn't like that cousin he made a will leaving his personal fortune to his daughter, who would receive when she turned 21 or got married beforehand.
It turned out that the marriage between Lord Coniston and Elvira's mother Bess Sedgwick was invalid, because Lady Sedgwick was already married and never got a divorce. It made Elvira illegimate, and she had feared that it could barred her from her inheritance. So she murdered her mother's legal husband Micky Gorman to shut him up. The irony is that the legitimacy of the marriage wouldn't have mattered because Lord Coniston named her his heir to his fortune in his will.