In Name Only (1939 John Cromwell)

Cary Grant falls for widow Carole Lombard and her cute daughter (Peggy Ann Garner); only problem is he's in loveless marriage to Kay Francis, who does all she can to break it up.

Drama isn't though sentimental or sudsy; Richard Sherman adapted Bessie Breuer's novel 'Memory of Love' (1935), of which one reviewer wrote:

Whoa. What a stinker this novel is and it's hard to believe one of my favorite Cary Grant movies – In Name Only – is based on this smutty and deservedly forgotten novel. [...]

In the novel, Alex is just a bored rich guy who likes seducing women, Maida is agreeable and pursues her own interests amicably, and Julie is too stupid to draw breath from one minute to the next. 

Has that great combination of J Roy Hunt and Roy Webb. Charles Coburn's in it too.

Carole's scar was the result of a car accident in 1925, when glass from the windshield badly cut her face. She endured surgery without an anaesthetic and her scar can still be seen in some of her films and photographs (dearmrgable.com). Gehring suggests in his autobiography 'Carole Lombard: The Hoosier Tornado' that it might have caused her dismissal from Fox. She was killed in a plane crash in 1942 aged 33.