In the Parker Pyne short story Death on the Nile, Pamela Grayle is the niece of Sir George and Lady Ariadne Grayle. In the story, she embarks on a Nile cruise with the rest of her family.
After the death of her aunt, Pamela told Parker Pyne that Lady Grayle had often had various delusions. She believed, for example, that Basil West, Sir George's secretary, was in love with her. This was ridiculous because it was well known that Pamela and Basil had an ongoing relationship. Pamela put forward the idea that Lady Grayle poisoned herself and did it in a manner to implicate her husband as a way of hitting out at him. Parker Pyne was sceptical because it did not conform to her psychology.
When the truth was revealed, Parker Pyne's review of the case suggests that Pamela was not herself complicit in the events leading to her aunt's death. He also remarked that she would get over it as she is young.
Pamela affectionally calls her uncle "Nunks" when speaking to him.