1: do not not start the day off with fats, for the average person who struggles with weight, eating breakfast will not stop them from overeating later in the day anyway, so you don't want to start the day off with high calories. A better idea would be PROTEIN- make a shake with maybe just 1 banana, a scoop of protein powder, use skim milk or almond milk as the liquid filler
Talk with her about exercise. This is crucial to weight loss- even 10 minutes of walking on a lunch break is a great place to start. Exercising regularly, even at low intensity releases endorphins which makes you feel better about yourself, which keeps people motivated (many people overeat when they feel like shit)
By the way you describe her, her diet is actually not that bad, so there are two options here: she eats the right foods but in higher quantities then she needs, or that she is a secret eater and gets extra calories from candy at work/junk food between shifts/ late night snack binges. In the latter case, the most important step would be to cut out junk food snacking or at least replace with low calorie snacks (carrot sticks and dip, celery, skim-yogurt, healthy cereal like raisin Bran, etc)