My DD is 16 months and still has 2 naps; she wakes anytime from 630am, has an hour on our bed for milk, toast and stories then goes back to bed after an hour - I can see what you mean about this being an extension of the night sleep. She naps for 90 to 120 mins, altho sometimes I can hear her chatting for up to 30 mins before she falls asleep, and the same when waking before she calls for me, so its really only 45-60 mins sometimes. Then she naps again at about 2pm, another 90-120 minutes; I try not to let her sleep past 4pm as she won't be ready for bed at 730pm otherwise. She sleeps really well, always has, no real signs yet of dropping either nap although on 'high days and holidays' she may do without one, perhaps if we are away for the weekend. I know Mums who get hardly any time to themselves so I'm not worried, even though it sometimes restricts the things we could do. After all, she's got years and years to learn to swim, dance, paint etc!