Sounds like she has decided she no longer needs the nap and I know from what you have said that she then falls asleep late afternoon, I had this with Amy and now I joke that it is a bit like having a pet dog as Amy needs to have a good run around everyday and if the weather is good then I choose the time in the late afternoon to have that run around. It can be hard work to keep a child awake (especially when you are used to having that little bit of time to yourself during the day) some children stop napping earlier then others so there is never a correct age to stop napping just be led by your child.

some kids just seem to need extra brain stimulation to tire them out so any extra activities or a play at the park or game in the morning .try putting her down an hour later than normal in the arvo and wake her after an hour.or if your able bring your nightly routine forward an hour or even half hour??my daughter was like this and that little extra activity or play at the park worked.i have done all these and they worked for me.