Deirdre Henderson

In the novel Mrs McGinty's Dead, Deirdre Henderson is the daughter of Edith and the stepdaughter of Roger Wetherby, with whom she lives in the Broadhinny house Hunter's Close. She has a Sealyham Terrier named Ben. Deirdre is a dull and “very simple” girl of around thirty years old, which was approximately the same age of Eva Kane's daughter. She saw the police draining the ponds and lakes to found the artifact with which Mrs McGinty's murder was committed. She believed James Bentley had killed McGinty, but when Poirot says he hadn't Deirdre became interested in the murder.

She was described by Poirot as a 'rather simple young woman—simple to the point of gaucheness'.

During the war, Deirdre Henderson worked in Kilchester as a VAD and as a chauffeur. However, her mother was very weak so she was also responsible for the house's domestic chores.

She was one of the three women called by Laura Upward (apparently), the night she was murdered, along with Sheelagh Rendell and Eve Carpenter. Mrs Carpenter and Mrs Rendell didn’t go there for different reasons. However Deirdre went, and found Laura’s house empty so she left. This was confirmed by a witness named Edna. It later turns out Edna saw another woman who had intention of killing Mrs Upward but had found her already dead.

The end of the novel gives a plausible explanation about why Deirdre's parents strictly wanted to control her. It turns out she had inherited wealth from an aunt, and the Wetherbys wanted to get hold of her fortune.

Portrayals
The character does not appear in the Agatha Christie’s Poirot ITV adaptation of the novel. Here the three women called by Laura Upward were Mrs Rendell, Eve Carpenter and Maureen Summerhayes. It is Mrs Summerhayes who finds the house empty. Since Deirdre is not featured, James Bentley pairs with Maude Williams at the end. The Wetherbys do not appear either, so here it is Mrs Carpenter who had forgotten McGinty's name.