Help! Main character named Iris

Help! My husbands grandmother is named Iris, I asked her recently why she was named that, and she said her mother was reading a book at the time with a character named Iris. She was born in 1940, so I assume the book was from the 1930s. Any ideas? Any classics with an Iris I don’t know about?

I’m sure she’d be delighted to read the book she was named after, she was dismayed that she never asked her mother what book it was. She has early stages dementia and has dealt with a lot of loss in her life, I’d like to bring her a kernel of joy.

Thanks all!