My daughter is currently in Y10. She loves science (all 3 subjects) and that's what she wants to study at university. She used to prefer physics but now she's realised she enjoys all 3 subjects.
Here is the "problem". She needs to chose 4 subjects as part as an application for a selective 6th form. In an ideal world she would like to take Maths, Physics, Chemistry and Biology. However, we don't know if not choosing Further Maths will compromise her chances of being accepted at Oxford or Cambridge (she's dead set on Oxbridge...).
We checked the courses requirements and Oxford doesn't seem to have FM as a "must have" but Cambridge does mention it as a plus.
If she takes FM, it means she has to drop a science subject but she doesn't know which one as she's potentially interested in several very different courses (physics, biochemistry, material science, natural sciences...). Basically all she knows is that she doesn't want to study medicine.
She does equally well in all subjects and is predicted 9s across the board so it doesn't help our decision.
We are not from this country so are not familiar at all with the system. I want to avoid missing some nuances, i.e. when universities say a subject is "recommended" or "helpful" in reality it means it's a "must". She's so motivated and hard working, I don't want to let her down as I see so many parents around us having themselves studied at Oxbridge and knowing the system inside out. We don't want to seek some advice from her school at this stage as we don't want to tell them now she is considering leaving after GCSEs.
As an aside she's also very keen to do some extra courses during the holidays to broaden her knowledge and help her decide what she wants to study. We did look at a few options but she was too young. If you have any recommendations of courses that can be done remotely (or not , for next year), I'd be very grateful. Again she told me many of her friends are doing some work experience this summer (organised by their parents) and I fear we're letting her down 
Thank you