Best not to say anything unless you are actually asked for support or advice . Until she is motivated to do something about her weight herself there is nothing you can say or that will help and might make matters worse. She needs to research this herself. The Nutracheck app or my Fitness Pal are both very good, as both enable calories intake and activity to be monitored daily on mobile phone. The body needs to be in 'calorie deficit' to lose weight ( points and syn counting often does not work long term as lifestyle changes are needed) . What is interesting to note is that on average one pound of body fat contains 3500 calories so eating 500 calories less per day will creat a deficit to support one pound a week loss for the average person. Equally interesting is that eating or drinking only 120 excess calories per day will increase body weight by a pound per month or 12 lb per year which is why weight gain can creep on without being noticed and where person is in denial about their intake. For young women, it can be small snacks, biscuits, chocolate and alcohol that adds empty calories to the weekly intake coupled with lack of portion control and not enough exercise to use up the calorie intake. Shift work won't help either. Unfortunately social media has too much content that suggests that weight loss is easy. It isn't, and takes huge amount of willpower and motivation. If you daughter does go on a diet you can support her by not having unhealthy food in the house, using smaller dinner plates for everyone, encouraging exercise like walking or jogging or taking up a sports, and making sugary treats like cakes and puddings an occasional treat rather than including them automatically after every main meal.