I can't believe what I am reading! You are extremely lucky that your daughter is not in the year below where you could face legal action for not ensuring that your daughter attended school. You claim that she is an adult and yet here you are complaining on her behalf. If she has medical problems, she needs to address these. Opting out is not an option - she has to adhere to the rules set by the organisation as she would if she were in the workplace. She cannot pick and choose. It is no argument to say that everybody breaks the rules.
You want us to agree with you and sympathise - it is clear that most posters do not share your views. We have tried to offer suggestions and advice, yet you continue to blame the school. You need to take a more objective view on this.
As for Oasis - are you serious? I disapprove entirely of Coca-Cola, which makes this product. Do you know what is in Oasis? I'd like to see you defend the following - I got this from the Coca-Cola website.
'Water, sugar, fruit juices from concentrates 5% (apple, strawberry, redcurrant, cherry), citric acid, natural berry flavourings with other natural flavourings, fruit and vegetable concentrates (blueberry, blackcurrant, carrot, apple, hibiscus), stabiliser (E452), acidity regulator (E331), preservatives (E202, E211), sweeteners (aspartame, acesulfame-K). Contains a source of phenylalanine.'
Some of these ingredients were, until a few months ago, banned in other European countries because early studies indicated a potential link to various cancers. At the very least your daughter is gaining no benefit from drinking this. You are irresponsible to insist that the school allow her to consume such a product. I hold a senior position at a top school in the country and I have instructed my staff that such oroducts should be confiscated until such times as the parent comes in to collect it. They are not permitted on the premises.
I wonder how your complaints would be dealt with if you were to report them to the local authority? You would get short shrift, I am sure.
Why don't you email Michael Gove with your issues and complaints about attendance and the rest? Why not suggest that sixth-formers should be allowed to do as they please and consume as much Oasis and cola as they choose? What do you think the response would be?
Or you could just accept that until your daughter goes into the workplace, she will have to follow the rules, get to school on time and do what is expected of her. When she starts work, she will realise that she will still have to follow these rules or she will have no job.