Is she getting enough protein/nutrients to make her full?
How often is she eating?
She could eat 6 small meals a day to keep hunger at bay yet still have healthy meals in healthy sized proportions.
Any time you "cut back on food intake to lose weight", you are hungry.
One thing that might help, is go on the same calorie/food intake restricted diet WITH her to see if you feel she could be getting full or still be MORE than a little hungry. I think that could help quite a bit & I would try it.
I'm sure she must still be hungry if she's saying that (sweets aside)....just regular food in general.
Also, be sure what she is eating is tasty, filling & change it up a lot to stave off boredom.
I know whenever I've cut back my caloric intake I am hungry & hungrier than normal. A big part of it is psychological while the other part of it is actually physcial: hunger.