I watched earlier, on TCM, "Easy Living", 1937, for the first time. She was great it it. I loved it.
The one thing about her, is it is easy to know her age in each film she did. She was born in 1900, so she was 37 in that film. "Mr. Smith Goes to Washington", she was 39. In "The More the Merrier", she was 43.
If you have seen that one, I'm sure you laughed as much as me. It takes place during WWII, and she works for the government and thinks it's her duty to open her home to roommates because of the housing shortage...but to no fault of her own, the roommates turn out to be Joel McCRae and Charles Coburn.
The romantic back and forth between Arthur and McCRae is amazing. It is sexier than any modern movie.
And then there's "Shane". She was 53. She played a mother of a young boy on the plains of the early west.
I don't mean to turn this into how sexy she was, and she was. But it took this talent so long to become the star that she is. She went through the silent era with not much notice, but finally her gestures, her voice, her acting, and added beauty was finally noticed in the talkies.
No one could make a scene with James Stewart, Gary Cooper, or Joel McCRae such so ...that it pulls the viewer into the scene, (at least for me), like her.
She was such a human presence in "Shane", not wanting her son to be like Shane, and more like her husband, while knowing that Shane, too, was a good man. In the end Shane buffaloed Van Heflin, her husband, to save him for her. And he sacrificed himself, as a gunfighter, to keep a good family, the center being the mom, Jean Arthur safe.