If good writers “kill [their] darlings”, then as with Newton’s Lex III: Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones in se mutuo semper esse æquales et in partes contrarias dirigi, every action has an equal and opposing reaction and great wriers don’t kill their characters, especially their cantankerous older women.
The aunts in PG Wodehouse are the example par excellence of the type of character writers absolutely shouldn’t top off.
The word character has a lot of meanings, including the dramatis personae of a story. Here, what character means is more precisely entry seven in the Oxford Learners Dictionary:
(informal) (used with an adjective) a person, particularly an unpleasant or strange one There were some really strange characters hanging around the bar.
With a bit of entry eight:
(informal) an interesting or unusual person She's a character!
And darlings defined as entry three:
the darling of somebody/something a person who is especially liked and very popular She is the darling of the newspapers and can do no wrong. https://www.oxfordlearnersdictionaries.com/definition/english/darling_1?q=darlings
While strange and unpleasant ‘characters’ might be tiresome in real life, they are the bread and butter in novels. They are the Cersei Lannister to Robb Stark or Little Nell. The ‘darlings’ die and the 'characters' survive to annoy and anger the reader and test the hero. Testing the hero is, of course, the raison d’être of epic literature. Epic meaning not just a long journey but also something outstanding.
For crime writers, the Golden Dagger Awards https://en.wikipedia.org/wiki/Gold_Dagger) signal great or epic writing. Looking back at women winners from the early awards, Ngaio Marsh stands out for two Silver Daggers: Scales of Justice and Off with His head. Both of these books have a cantankerous older woman.
What is the difference between an award winner and an also-ran?
In Photo Finish, another Ngaio Marsh book—which didn’t win any prizes—the pushy older woman is killed off. Although Alleyn’s ‘darling’ wife features in Photo Finish, she is an intelligent and beautiful painter. She doesn’t test the hero to the same extent as an irritating upper-class matriarch.
Marsh kills off The Sommita who is not only a character, but the most unpleasant, strange, and interesting one. She is a diva—an opera singer with a temper and unreasonable demands. Her boyfriend is an American businessman who has bought an island in New Zealand. It’s never explained why he chose New Zealand. Perhaps the choice of location relates more to the writer’s love than the character’s; perhaps keeping the businessman and murdering the opera singer was also the author's preference; as the saying goes, it would have been better to kill off this darling and keep the Sommita.
Dame Alice in Off with His Head is perhaps the nicer of the two matriarchs in the award-winning books, but she still fits the bill as an ‘interesting or unusual person’:
I don’t know,’ said Dame Alice with difficulty and passion, ‘I don’t know who yar or what chupter. But you’ll oblige me by takin’ yerself off.’ She turned on her great-niece. ‘You,’ she said, ‘are a blitherin idiot. I’m angry. I’m goin’.’
Parsing her no-nonsense speech adds to the joy of reading about her. She is in her nineties, lives in a tumbledown castle, and has definite ideas about how life should proceed. She, however, likes Inspector Alleyn and helps him with his investigation. In Scales of Justice, our basilisk, Lady Lacklander calls up Scotland Yard and demands that Alleyn be sent to investigate. She then tries to run his investigation. The reader enjoys Alleyn putting her back in her place.
‘That’s a remarkable woman, Fox,’ Alleyn said. ‘She’s got a brain like a turbine and a body like a tun. My mother, who has her share of guts, was always terrified of Hermione Lacklander.’ … Alleyn opened the door and switched on a light in the car. ‘Now tell me,’ she said, after she had heaved herself in, ‘tell me, not as a policeman to an octogenarian dowager but as a man of discretion to one of your mother’s oldest friends, what did you think of Occy Phinn’s behaviour just now?’ Alleyn said: ‘Octogenarian dowagers even if they are my mother’s oldest friend shouldn’t lure me out of doors at night and make improper suggestions.’
Readers can feel pity for the other dramatis personae having to deal with these ‘characters’. And although we all know that Aristotle put events before character, he also put pity and fear before love or anger (Poetics, Trans. Anthony Kenny. Introduction: Tragedy and Emotion). Writers, if you want to win an award, don’t kill your characters.