DS stopped at about 2.5yrs. DD is 19 months and 30-60 minutes is normal for her. She went down to one sleep at 10 months. So won't be too surprised if the day sleeps go before 2yrs (unfortunate though that will be). If she sleeps longer than 1.5hrs it is impossible to get her to bed at night.

DS mucked around like that though, and then went back to sleeping well for months, so don't give up hope!