Thanks for the news links.
I'm not a parent so I'm not going to wag my finger or be too critical but I also think anytime there's a "kids & guns" situation even for a brief period or short trip, you(the license holder or owner) need to be careful.
Young children are naturally inquisitive & curious about weapons.
My nephew is 10 & often asks me when we can go target shooting or to the range.
As stated, the DA might file charges but I highly doubt it. I'm sure the kid's mom went off like a ICBM.