to hit her you press Z, but when you get the warning(!) sign you have a few seconds to dodge (either left or right with the arrow keys) but you must time it right that her head butt still doesnt hit you when she shifts back (cuz you dodged her), she and one other enemy have alot of health so you have time to hit her twice if you time it right but don't get greedy and hit her three time cuz then you cant dodge, you have a stamina bar so keep an eye on it cuz if you run out you cant dodge, you use the same bar for hits