this is GREAT advice. Also, she should try to get an accurate gauge of how many calories she's currently eating - just to be aware of where she's at. Then, rather than cutting back by a huge amount, she can slowly cut out a few extra calories, here and there, while focussing on eating healthy.
For example, if she cuts out junk food/processed food, and replaces it with whole foods/fruit/veggies, then she's doing two things - reducing calories and eating healthier. She WILL lose weight this way, provided she's also exercising. Nit-picky calorie counting is only necessary after the healthy habits have been established (though it's good to remember that even healthy foods, like olive oil, can be high calorie and will cause weight gain if you're overeating them).
Eventually, she might plateau... assuming her calories aren't already very low, she can gradually cut back a bit more (doing it gradually will keep the body from going into starvation mode).
When she gets down to a fairly low daily intake (depending on her lean goal weight and her activity levels, it could be anywhere from 1300-1800 a day), she can periodically spike her calorie intake - perhaps one day a week (though I think it's best if the increased calories still come from healthy food) - this will help keep her metabolism high, and keep her from feeling deprived. But the rest of the time she needs to be strict. And stay active - weights AND cardio.