When my kid was three or four, I called the sheriff's business number, asked to talk to the 911 office, and asked them if I could have my son dial 911 and talk to them, for training (his). They checked if they were busy, then said OK.

It puffed up his chest a bit, but we talked about emergencies, how to get help, why we don't call 911 unless it's an emergency, etc.

I suppose if everyone did it they wouldn't be agreeable, but no one does, so you should too. :)