In the novel After the Funeral, Geraldine Carson (née Abernethie) was the sixth child of Cornelius Abernethie, and younger sister of Richard Abernethie. She married Anthony Carson and had one daughter, Rosamund. Geraldine was already deceased at the beginning of the events in the book. Little is mentioned about her except that she had died somewhere abroad.
The Abernethie family tree is simplified and abbreviated in the ITV TV adaptation but Geraldine's branch is still represented. Here she becomes the mother of both Rosamund and Susanna Henderson who has been renamed from Susan Banks and who came from a different branch in the original. Geraldine is mentioned but not seen on screen as she is already dead before the events in the plot. Her husband's name is not mentioned but given that Susanna is not married, and her surname is Henderson, this would suggest that her father and Geraldine's husband is Henderson as well, rather Carson as given in the original.