As to safeties, remember your firearm safety training, safeties are mechanical devices that can fail. You cannot trust a “safety” to work. I recall as a very young child, the first thing I can remember being told, my father told me not to rely on safeties, then related a story about a friend of his. Firearm safety is based on redundancies, if one rule is broken, you are still likely to be safe.
Yes, you need to be comfortable in whatever you carry. Young children can be of concern when there are firearms involved. When my daughter was young, the firearm was either on my person or in the safe. Whenever I showed her the firearms (unloaded), I would always explain the rules of firearm safety, or when very little, just don’t touch. My primary concern was not her finding one of mine, but what would happen when she was not with her parents, at friend’s house, etc.
When she was young, I would show her the unloaded firearms, and let her “play” with them, which gets boring real quick when they are inert. I would also explain how they worked, proper handling, how to make them safe, and break them down. Every time she was around when I cleaned them, she would get another safety lesson, how to make them safe and break them down. She learned real quick not to be around when I was cleaning my firearms. At about 8 years old, she decided she wanted to learn to shoot. By then, she already knew firearm safety and how to properly handle them (though she had previously only handled them unloaded).