My 6 month old baby has this hard line on the top left of her head. It's almost like a hard vein, but it feels like bone. Is this normal? What is it? I'm very worried and can't find the answer on the internet.

MAybe it is best toget the answer from a physician. Sometimes babies are born with complications and this is something that you should check out. It could be anything and it is best to get the answer from a physician. If you don't have medical insurance or you are worried about the bill go to the emergency room.