Baby curls! Baby curls are the cutest curls of all.

I have no idea how to answer your question - I had a boy and he didn't have hair until he was 2!  Baby hair is usually very fine for the first several years.  Adult curly hair is usually coarser than straight hair, and also more dry.  I can only assume that baby hair has similar traits. 

I don't remember when the skull would be considered solid enough to not worry about a hairband, but I'm sure if it is not too tight and not left on all day, you could dress your precious baby girl up with the hairband.