My five-year-old just gave up. He practiced well at home,
but shy to play even in front of his teacher, who was not very helpful in this sense -- ok if my son didn't play and let half an hour passed.
I guess it depends on kids' personality.A five-year-old girl who has the same teacher as my son's knows all the tunes already.
However, everyone, including a few music teachers suggested that we start with piano so that kids can develop a sense of right tones.
So we will return the violin and buy a piano:).
Good luck. My hu*****and is patient and ok with music, but he said it is SOOOOO hard to teach our son to focus, etc.