Twice, Enola offers laboring boys £5 for their clothing, about £350 (US$455) in 2020. In 1880, a common laborer earned about 3 shillings 9 pence per week, or £9.15s. per year. Enola offered the laborers six months' salary for their clothes.
Enola and her mother are shown keeping bees, a hobby Sherlock took up in retirement.
Millie Bobby Brown and her sister Paige, fans of the books, approached author Nancy Springer with the intention to star and produce the film under their own label. Legendary Entertainment offered financing while Millie Bobby was filming Godzilla: King of the Monsters (2019) for the company. For this film, Millie Bobby was paid $6 million for her starring role and an additional $500,000 as a producer fee.
Millie Bobby Brown is one of the youngest actresses to have a Producer credit at age 16.
During the montage of images introducing Sherlock Holmes, Henry Cavill's head is superimposed on an original illustration of Holmes by Sidney Paget.