As a teacher, you are working with what your students provide you. If they don't provide you with anything, you can't do anything, except, basically, have a practice session. And that is not your fault.
Being that she is 9, if her parent wants her to progress, she needs to make her daughter sit down and practice the required amount every day. If she doesn't, she has nothing to complain about, and nothing to criticize you for.
My students don't practice much, either. That's why in every lesson I'm not just teaching them new information, or trying to cement and perfect ideas in their mind; I'm also teaching them how to practice. And usually, by the end of the lesson, they're playing the piece 10x better than before. I constantly remind them during at the end of the lesson that I'm not just teaching them new stuff- I'm teaching them how to practice, and they should practice at home the way I have them working during the lesson. I also make sure to tell them that if they can make that much progress in one lesson, they can definitely make that much in one week! Usually this embarrasses them, and they kinda duck their heads, because they know very well that they could be doing more.