My 3yr old daughter woke up with a swollen cheek, one swollen eye and a swollen upper lip. Her sheets are clean, what could cause this? Pedi worthy?

Yes. You need to have the pediatrician see what the cause of this is.
Possible allergy. It is possibly caused by allergy to something, it is called angioedema .But there are other possibilities like and the child should be checked by your pediatrician asap.