[1] Following that, she signed up to continue with Bath Spa University, taking their "Writing for Young People" master's degree, offered by the School of English and Creative Studies there.

[6] Her fourth book, Close Your Pretty Eyes , is about 11-year-old Olivia, who has spent most of her life in the care system, with many different foster parents, most of whom she has despised and treated badly.

In the book Olivia believes that she encounters the ghost of Amelia Dyer, real 19th-century baby-farmer who murdered many of the babies she was paid to care for.

[15] Nicholls contributed to Mystery & Mayhem by Egmont Publishing, published in May 2016 along with 11 other authors including Julia Golding, Katherine Woodfine, Clementine Beauvais, Elen Caldecott, Susie Day, Frances Hardinge, Caroline Lawrence, Helen Moss, Kate Pankhurst, Robin Stevens and Harriet Whitehorn.

[16] Her sixth book, Things a Bright Girl Can Do, published in 2017, is a historical novel set in England between 1914 and 1918.