[3] McNicoll's debut novel, A Kind of Spark (2020), follows the efforts of an autistic[4] eleven-year-old girl, Addie, to establish a memorial to the witch trials in her Scottish hometown.

[15] Her third novel, Like a Charm, was published in February 2022 by Knights Of and was also Children's Book of the Week in The Times,[16] as well as being reviewed as "another fiercely gripping, superbly original story" by The Guardian.

[17] In 2022 McNicoll also wrote a story as part of the crime anthology The Very Merry Murder Club[18] edited by Serena Patel and Robin Stevens.

A Kind of Spark was optioned for a television series from CBBC, with McNicoll acting as co-head writer on the programme.

In an episode of In the Reading Corner, Nicoll talked about her nuanced exploration of teenage bullying and the stereotyping of neurodivergent characters.

[27] The longlist for The Adrien Prize 2022 was announced on twitter and included: The Night the Moon Went Out by Samantha Baines, The Secret of Haven Point by Lisette Auton, A Flash of Fireflies by Aisha Bushby, Wilder Than Midnight by Cerrie Burnell, The Great Fox Illusion by Justyn Edwards and The Extraordinary Adventures of Alice Tonks by Emily Kenny.