Pearce was inspired to write Dear Mrs Bird by a women's magazine from 1939 she stumbled upon back in 2011. She began collecting wartime magazines to form the premise of her World War II London-set novel. Following a bidding auction, Pearce landed a two-book publishing deal with Picador in 2016 with potential for more. Scribner won the U.S. side of the deal. In advance of Dear Mrs Bird's release date, 42 optioned the novel for television.
