Discuss, don't avoid.  Have open and honest age-appropriate conversations with all members of your household about firearm safety.  Establish clear "don't touch" rules with underaged children and what do to when they do see a firearm.

Create "what if" scenarios for all household members as practice for how to respond in various safety-related situations.

There are many storage and security devices that can keep your firearm secure.  New solutions allow more mobility and options while preventing unauthorized use.