Could she be getting teeth? Charlie go his first 2 at 5.5months & we had a nights like that for about a week. It was like he was 3wks old again....we were so very exhausted. Have you tried perhaps giving some panadol? Might not be, just a suggestion. We have never had trouble settling Charlie back to sleep, or sleeping at least a 7hr stretch at night from about 5wks. So if something like that happens we know somethings wrong & so far each time it's been teeth.