The Thin Red Line is a superb film, but Malick is a divisive director. Some really can't abide him. I think he's astonishing.

To be fair, I've met several women who like war films (including my wife, who particularly likes The Bridge on the River Kwai, The Great Escape, The Longest Day, and the Band of Brothers TV series, to name just four examples - though she's not seen The Thin Red Line, but did like The Tree of Life). That said, I do understand where you're coming from, as the genre is often stereotyped as "blokey". Same with westerns (which my wife also loves by the way, along with gangster films - basically she's into pretty much everything).