I have talked about the dangers and the specific training/drills to mitigate those dangers with my wife. This helps her to realize that the cave is not going to mysteriously swallow me, that if I die doing this, it will almost certainly be my fault. She also realizes that I value my life enough, particularily as it relates to her, to not take foolish risks with it.
What I am trying to say, is that MORE information, more openess and honesty, has worked for me.
While we are on the topic, use this as a chance for introspection. Do you, honestly, feel that you can cave dive safely? Can you say "No" to that next turn in the passage, when you are at your limit? Can you say "No" to your buddy when they want to dive past your gas limits, or dive without running a primary, or visual that jump, or dive past your training? Do you know your own weak spots that might get you into trouble? Are you too stubborn to turn a dive that "just isn't right"?
Sorry to sound preachy, but ever since I became interested in cave diving, we have had at least one death every year that was VERY preventable. And in many of those cases, the deceased had enough training to know better. The latest incident has caused me to think about cave diving, and safe attitudes neccesary to partake, rather heavily.