In my eighties, my best friends are in their fifties, and I have many friends at university. It keeps one young, and up with the vocabulary. That's terribly important, especially for a writer. Women's courage is rather different from men's. The fact that women have to bring up children and look after husbands makes them braver at facing long-term issues, such as illness.
Men are more immediately courageous.
Lots of people are brave in battle. The way Sylvester and Julia look is not described in much detail. I have deliberately left Sylvester and Julia's appearances to the reader's imagination. Loveless marriage is a theme in many of your books, never more strongly so than in An Imaginative Experience . Yet most of your characters still seek an enduring romantic partnership.