Legal obligations and rights of the parties

Questions 1. Fatima is an 18 years old girl who just graduated from school. Since then the only thing she does is eating takeaway junk food, use her social media apps like snap and tiktok for hours at night and sleep all day. Her teacher from school realized that she is wasting her youth with these harmful activities so she told her that if she only eat health, use only Nokia phone with no apps and delete her snapchat and tiktok accounts, exercise to be fit and study at a university. Then Teacher will buy her a Rolex watch when she completes the university and graduate with A grade GPA as well as keep her weight below 55KG. Fatima got excited and did exactly what the Teacher told her, so after 4 years she graduated from the university with GPA of A while staying fit at 54KG, and asked the teacher for the Rolex. The Teacher told her that I only wanted to encourage you and to make you a better person. I was not serious about giving you a watch. However, Fatima got upset, as she believes that the teacher should honor her promise, because she was doing something extra, she has to put extra time and efforts to achieve it, and she was not obliged to do it. Explain the legal obligations and rights of the both Fatima and the teacher. Give examples and references to cases where applicable