Britain's first women police constables were employed in 1915; an important example of women showing they were capable of doing previously exclusive "men's work" during the First World War and not standing down afterwards.
In the movie Rose Gooding is Irish migrant. In real-life she was born in Lewes, Sussex, England. Jessie Buckley, who plays Rose, was born in Killarney, Ireland.
Although the actual events occurred in Littlehampton, the filming did not take place there. Instead nearby Arundel and Worthing were used. Arundel was used for town and street events. All the seaside filming was carried out in Worthing.
In real life, Olivia Colman is well known for using colourful language and liberally dropping the f-bomb in interviews.
Unlike in the United States, the UK has never had a law against interracial marriage or relationships. Couples might have faced discrimination and prejudice but such relationships weren't prohibited or illegal at the time the film is set.