Be sure you have the skills to handle your craft with a wide margin of safety
Know you can handle the canoe one-handed while digging some toy out from under a pack
Know how to assess your skills & assess the hazards
Start small
Short days
Keep flexible
Work with their schedule
Allow lots of time just to explore
Rapids
Weather
Water temperatures
Bring some extra items but be careful not to overdo it
A couple favourite toys
Your load will be larger and the kids don’t carry much
An overloaded boat is unsafe
Bring lots of clothing options
Kids will not be happy for long when wet & cold
Kids WILL get wet
Kids will improvise