She is 9, she may not loose weight, maybe just grow taller and maintain. You have to change the whole family's eating habits and what kind of food is in the house. You can't just restrict one child. Is she is sports/activities? Anything that will increase her activity level and self-esteem will help get her mind active and keep her from absent eating.
A quick story, young girl about 5, very chubby. Mom terribly worried about her and trying to make her diet. Dad stated taking her on bike rides and signed her up for basketball at the park. (she was not tall, he did not play,just on of her friends was doing it, so she was up for it) I think she was about 9 by that time, still struggling with her weight. I saw hew 2 weeks ago, she is 13, 6ft tall, legs up to there, thin, gorgeous. And she is in 8th grade and college scouts are coming to her park district games!
The point is help you daughter pick something that she can re-direct her attention, and her self worth is very fragile right now so be careful.
Good luck to both of you.