Great trip report and glad to see you are introducing your kids to nature. We need a lot more of that. They sure look happy.
You probably already know this, but for others that may be reading this and thinking of a backpacking trip with kids, it is recommended to keep the pack weight to a maximum of 20% of body weight, and for smaller kids, many recommend 10 to 15% of body weight. My youngest son just turned 9 not too long, and I try my best to keep his pack at 15% or less. For my son, I'm shooting for around 10 lbs.
Thumbs up for being a great Dad and Mom!