Lisette suffers from an anxiety problem, which can quickly become very stressed if she is confronted with situations that she has no control over. This is what happens at school.
She is often confronted with various things that only stress her out, such as those studies that are not good, because of her ADHD which prevents her from concentrating fully and not understanding everything at first sight.
Then, she is confronted with the judgmental gaze of others, surely who judges her because of her height, being an abnormally tall girl, her enormous weight, especially since she is wearing a uniform that does not fit her new weight and that takes time to get a new uniform. She imagines so many scenarios that it increases her anxiety.
Then, she gets bullied by some groups of girls who use her as their way to let off steam by insulting and intimidating her, especially since some of them are jealous of Lisette's huge breasts. Since Lisette does not defend herself, she is the perfect easy target for thugs.
And finally, physical education classes are a nightmare for her, already having a complex of being fat, has the impression of humiliating herself in front of everyone, when she has difficulty making physical efforts.
When she feels overwhelmed by so much stress, other than trying to control her breathing, she will stuff herself with lots of food to try to relax, eating her stress. But this creates a vicious circle, making it worse for her weight-related situation and increasing her stress.
Lisette really needs help, but luckily these friends are trying their best to help her.
(Each character wearing a uniform here is in an adult school, and Lisette is between 20 and 21 years old, to avoid any quick judgments. Thanks.)