How Long Will The Mild Pain On Scalp Take To Subside?

Hi.. my Sister in law got hurt in her head during the landing of her flight. ( the panel sheet of the ac duct in the aircraft fell on her head). This was on Feb 14th. She was injected painkillers at the airport itself as the pain was un- bearable.. We got her CT scan done the same day n that showed hairline fracture. the doctors initially gave medicines for nausea n pain with which there was some relief in the first week. After that the pain continues till now.. it is mild and more in the scalp area but sometimes it becomes severe. Pls advise how long will this take and do we need to take any other tests...