There are two basic approaches, and both have value. Childproofing your guns (locking/securing them, or the ammo) and gunproofing your children (teaching them what guns really are and what they really do).
Both are needed. How much, of either is your call, for your situation.
Some folks teach their kids well, but keep things locked up anyway, because of other people's kids who might be there and don't know safety.
If you don't teach your kids, they might be the ones at risk in someone else's house, as well..
I grew up in a house where my Grandfather's shotgun lived loaded behind a kitchen door, and had done so for more than 40 years before I got there. Somehow, Mom survived that, and so did myself and my younger brother.
One memory I still have from my childhood is trying to lift my Dad's .357 S&W (while he watched me at about age 5 or 6
)
When my daughter could pull back the slide on my .45 I knew it was time that chamber empty mag loaded wasn't completely safe anymore...(and yes, I tested the kids on this)
My kids learned what guns really were, and did. Many children today don't get to learn that.
When kids know, they aren't as curious. When they aren't curious, they aren't tempted to find out when you aren't around. And if they know what they should know, even if they did get to one without you around, they are less likely to have an accident. (applies to lots more than guns)
Unloaded guns are at best, awkward clubs. Pretty child safe without trigger locks or cables or a safe, etc., if you ask me..
Does your "ready" gun need to be fully loaded? Your situation, your call. For me, I'm fine with something that can be loaded "quickly", and easily.
What has worked in my family for generations may not be applicable in your situation. You just have to use your best judgment.
Be aware that if a child has seen you do something a couple times (maybe only once) they "know" how to do it. Maybe they can't do it (yet) and maybe they can't tell you they know how to do it, but if they want to do it, they will try.
My son, a 4, "drove" his grandfather's car. Got in, turned the key to "ON",put the gear lever in "D", and steered it as it rolled away. He might even have made the turn around the house if he had turned the key to "start" and had the engine running (so the power steering worked).
Daughter gave a friend detailed, step by step
accurate instructions how to operate a complex multi component stereo system, while sitting on the floor, with her back to it, playing with a dolly, at an age before she could read. Stereo was on a shelf 6ft off the floor (to keep it out of children's reach), she had never touched it, couldn't reach it, but had seen me do it, often.
They DO learn. Often sooner than you think. It is important that they learn what they need to know.