Why Do Infants Cry After Sleep?

I am a preschool teacher but my concern is my 14 month old grand daughter. She crys from wake up time and often throughout the day for no reason. We feed her, change her, make sure she has love and hugs and everything we can think of to help her sooth her but nothing works. She doesnt seem to have any of the noted austism signs but should we have her checked for these things? Or is my grand daughter just wanting her way ?