Once you both know the answers you can move in many possible directions. She may need to enroll in classes that are more in line with what she wants to do. Perhaps she could write and/or visit a college, tech school, or job site that offers training/careers in her interest areas. Even going to the local high school and talking with the career/guidance counselor may help.
I would also encourage her to get involved in her own school's activities -- clubs, sports, teacher's aide, etc. Perhaps the school counselor can help her. In large schools, students sometimes just don't feel connected and this makes them seem unmotivated.
Continue to talk with your daughter and listen. The issues I've raised may not have anything to do with her lack of motivation. But if you are listening, you will hear what the problem is and you can solve it together.