Hello,
I’ve been monitoring this forum for a while but haven’t had anything I thought I could add. But now I thought perhaps I could try to contribute a little. I’ve been playing for a little more then two years now, I’m not great but I don’t suck. Well I hope I don’t.
Anyways I just started teaching some of the youth in my area how to play the tin whistle and I find it a lot easier to teach them if I treat it as a game instead of a lesson. I was wondering if any of you have any good ideas for teaching children. I don’t have any teaching experience so this is all new to me. So far the lessons are going well but I would like to keep there interest.
Any ideas would be appreciated. Thank you. 
Start the little ones out with a 5 tube pentatonic “no wrong notes” panflute or a 4 hole Ocarina. If you think they have the coordination for a 6 hole whistle, by all means get them started with simple “play by ear” tunes.
Children are amazing mimics and can copy your fingering and sounds without having to read music. Get them to “sing by rote”, that is, make them sing the notes and the rhythm with thier voice and then transfer this to the whistle. The repetitious singing sets the song pattern in the brain so when they apply themselves to the whistle they will automatically correct thier own mistakes.