16 month old toddler fell out of rocking chair hit her head I heard her neck pop should I take to er

She cried for about one minute and has been playing since

How long since it happened?

How long since it happened?

About 20 minutes ago

I don't know how serious it is. I don't know if you need to go to the er or not but I do know any head injuries they say - keep awake for an hour.