Hi Antony,
I belive at that age they have to go into Kindergarten wich is pretty good I undertsand not that I have tried it! This is based on the last time I was there a couple in my group had a 7yr old and they had a problem getting him into our group. Turned out the little git was better than most of us! They do stick them on skis though.
we took our six year old with us. he had a few days in the ski creche than came out with us. instructor was fine about it.
and yes he was better than me and the wife