Wont sleep but needs too!

My baby is 1 today and i know its been an exciting day so she hasnt napped at all maybe 10 or so mins in the car. She usually naps around 11am and its now 6.30pm and she is so tired but wont sleep? Shes lying beside me just blinking and looking at me. Im starting to get a little worried because she just isnt acting right, shes ate well and perked up when we got to the soft play centre but shes been so tired and unbothered about everything since about 12.30pm.