Tell me, it's been 11 days, the nurse came today. The baby has a cepha…

Tell me, it's been 11 days, the nurse came today. The baby has a cephalhematoma since birth, the hospital said don't do anything with it, but the nurse said to apply Arnica cream 3 times a day. Second question, should we give water, the hospital said no, even though there is a slight jaundice, and the nurse said to give it about an hour after eating. Has anyone had this experience, what do you think who is right?