I'd be really interested please to hear how long other people's 4 and 6 year olds sleep for.
My 6 year old tends to sleep 9-9.30pm to 7.45am, bedtime starts MUCH earlier but he has ASD and there is an elaborate routine we have to go through culminating in staging with him until he is asleep. He would sleep longer in the morning at weekends I think but the 4 year old invariably wakes him up. So total around 10.5hrs.
My 4 year old has no diagnosed issues but just doesn't seem to be keen on sleep. He sleeps 8.30-8.45am until 7.15am ish but sometimes earlier I suspect (he has a grow clock and waits for the sun to come on but makes noise!). He will, if allowed, stay up later but always wakes up at the same time regardless of bedtime! So also around 10.5hrs.
This doesn't seem enough to me for either of them but maybe I'm wrong?! I would love some comparisons please!