Looks like great time had by all.
One thing to be careful of, and this can happen to all of us. With four people at your launch, one adult handling the camera, one adult helping the two kids manage the ignition system, it seemed like in a couple of launches no one was actually LOOKING at the ROCKET during the final count down.
It is not uncommon for an "event" to happen to the rocket on the pad just before launch (wind blows the rocket over, the screw holding the rod comes loose and the angle flips horizontal, your dog jumps out of the car ).
Rocketry has a lot to teach kids, including opportunities to teach safety. You can even appoint one of the kids to be the "safety officer" who has the authority to call "go/no-go". The "mindset" you can learn from launching rockets SAFELY can carry over into other activities as well.
Hoping you guys get lots more straight trails, laughter, and fun!
Tom