The character of Beau has always been a puzzle for me. On the one hand, he's such an important part of the story...he's our leading lady's true love and soulmate and he's the one who rescues the entire extended household from financial ruin in the depression and sets up financial security for Mame and Patrick for the rest of their lives. He makes everything that comes after his entrance into the story possible.
But, on the other hand, he appears in less than a handful of scenes and is never mentioned again after his untimely death. I've always wondered if his brief presence is meant to underline that he's NOT actually any more important to Mame than any other character who appears in and disappears from the story in a scene or two, meaning that he and his money were simply a means to an end and not a great love or a great impact of any kind in her life. That characterization makes Mame much more of a mercenary than I think she's meant to be, but it's also valid.