Thanks Ladies.
Is it normal for them to have a much shorter A time in the morning? In the afternoon, she can go 4+ hours easily, but in the morning no more than 3. In fact, this morning, she was ready for sleep after 2 hours, despite 13 hours of uninterrupted (well, I didn't hear her!) night sleep. Maybe she's coming down with something. Thanks for your advice anyway. Just really worried about her not sleeping at childminders, but I guess it's only 2 days a week, so I'll just have to make sure she gets lots of sleep on the other days.