I agree with Brendy. My daughter started when she was three and a half (she's fourteen now and still dancing). I don't remember exactly how it came about that she was taken to a class but I remember that the teacher (Patricia Kennelly in San Francisco) demonstrated a simple step and then asked my daughter to try and do it. She made the attempt and did it pretty well because the other kids started applauding her effort. From then on she was hooked.

My advice to parents is: don't push your child too much. Just be supportive. In our case both my daughter's mother and I played Irish music so she had been around it all her life. I suppose that helped a lot.

Regards
radriano