What Causes Severe Headache And Vomiting?

my niece is suffering from severe headache associated with vomiting. (soft green and sometimes watery content of the vomitus) she has sore eyes but about to heal, the doctor found out on the urine analysis there is blood and pus is 7-12..according to my niece, she had a concussion about a month ago, she s not sure of it. she is 6 year old about 30 kilos..what would be the initial findings for that? and what would be the possible cause of her headache?