I agree with MoN's suggestion to encourage your daughter to ask the teacher what he was looking for.

Will the graded paper be sent home soon so you can see how the teacher arrived at the 75%? If so, I'd suggest waiting to see that, and reviewing to see whether the teacher seems to be unreasonably changing his standard. If he is, I would suggest meeting with him yourself to address the fairness of his grading system (or lack thereof).