I saw Ann Vickers (1933) which starred Irene Dunne. Based on a novel by Sinclair Lewis it's a short film at 76 minutes but could easily have been made into a longer film with the material it covered. Definitely a pre-Hay code film where the heroine is assumed to have an abortion, scenes in a women's prison where a convict is executed by hanging and another convict is being whipped, the heroine subsequently has an affair with a married man and has an illegitimate child and the film is allowed to have a happy ending.
The film starts in 1918 where the USA becomes involved. In an early scene where there's a party for the departing soldiers, I saw a man looking rather admiringly at Irene Dunne. That is irrelevant to the film but I've checked and it was a cameo appearance by the film's director John Cromwell.
There's a scene in a hotel room with Irene Dunne and her first lover in the film. The camera pans away from them to the open window where we see a cinema with a sign announcing next week's film "Joan the Woman". The scene darkens for a moment and then lightens again to show that a week has passed and the next week's film is "Shoulder Arms". That of course is the Chaplin film. That may be a bit of a goof as Shoulder Arms was released in the States on 20 October 1918 and WW1 ended of course on 11 November 2018.