We never had a seperate "kid Dinghy" but it was a welcomed event to send the
kids solo to the beach and say "don't come back for at least 30 minutes". My wife would then look at me and laugh and say... "more like 7 minutes kids". Ha ha ha....
Adding a second dinghy is pretty hard for most boats, but letting them drive and get familiar with the "family dinghy" also made us and them more comfortable taking the dinghy to the beach solo, since they had plenty of good experiecne under our watchful eye.
Be sure to teach them the seriousness of the damage a dinghy
propeller can do to an arm...leg....etc. Wearing the kill lanyard needs be done by the parents for the
kids to do it also. If you tell them to wear it but you don't....well....