Katherine Greenshaw

In the short story Greenshaw's Folly, Miss Katherine Dorothy Greenshaw is living at Greenshaw's Folly, a large house built by her grandfather.

Miss Greenshaw was stabbed to death with an arrow, but it was made to look like someone shot her with a bow and arrow.

Portrayals
In the 2013 ITV adaptation of Greenshaw's Folly, Katherine Greenshaw is portrayed by Fiona Shaw.

The portrayal in this adaptation is more sympathetic than in the original story. Although eccentric, she was seen as a kindly person who had the reputation of extending a helping hand to people in need. She is friendly to Archie Oxley, Louisa's young son and takes him around the estate and garden. She later gave him a present of a toy archery set which had been lying unused in the nursery.

An intellectual, Miss Greenshaw here had a double first in Chemistry at Oxford and at the time of the events in the episode, she was busy writing a codex on medicinal plants. She had poor eyesight and distilled her own atropine from belladonna to make eyedrops (thus weaving in the plot from The Thumb Mark of St. Peter).

Miss Greenshaw is killed in roughly the same manner as in the original but here there is the addition of sedation/poisoning by atropine. In this adaptation, she did not leave a will but the details of her family tree are slightly different here. During the denouement, Miss Marple disposes of Nat Fletcher as a false claimant by producing a birth certificate from Somerset House. In a book of Shakespeare's sonnets, Miss Marple also finds a birth certificate, showing that Miss Greenshaw's heir is Alfred Pollock, an illegitimate son from an unmarried union with Thomas Pollock.