I would make an appointment with your pediatrician and have them check it. It could be a number of things and searching on the internet will only make you worry.
I would say that a visit or call to her paediatrician is a good start. More than likely, it is nothing, but, it is always best to be safe than sorry.
Kattt is right, searching the net causes lots of worry, LOL, I know, I am an expert at it.