My now nine year old slept through at 9 weeks then I had my now eight year old who slept through at four years, then I had my now 3 year old who still wakes through the night ( only once at around 2am) then I had my now 2 year old who goes to bed at 7pm and sleeps until 7.30am. I also live in canberra, I bought some small electric heaters (the bar type) and I leave it on low all night in all the kids rooms, this seems to have helped in the winter months. I think it depends on the child and it seems to flow through to when their older too, my nine year old is a terror to wake in the morning but my eight year old gets up as soon as I say to.