Hi everyone! I am from Oxford, England, and as such I'm not really up with this whole applying to American Universities thing, so I was wondering if you could help me? Posting in the Yale forum because, well, it seems like a nice place

and I am applying to Cambridge here so I think that equates to Ivy League. Anyway, I was wondering in general about what my chances were at getting in to the Ivy Leagues - whether it's worth my while to take the SAT and have a shot at it. So here is about me:
I'm in year 12, which I think is the same as 11th grade, I'm in a private all-girls school which is really academic, I don't really know where I am in the year group but I reckon probably top 15/90. I want to major in English Literature.
10 GCSEs:
English, English Lit, Maths, Biology/Chemistry/Physics, German, French, History, ICT (All A*) Art (A) -- I've also done Latin, Geography and Religious studies but couldn't fit them into my timetable for GCSE.
5 AS levels: English Lit, History, French, Maths, Critical Thinking predicted AAAAA
Will take English Lit, History, French, Maths A levels.
Activities in School: CCF (combined cadet force, RAF section), Run an English club for year 7s, 1st XI field hockey team, cello to grade 5 standard (that's average/good), Gold Duke of Edinburgh award, charity work for school charity, Prefect (voted to position by girls, staff, old prefects)
Activities out of School: Ballet, Modern and Jazz dance to grade 8+ standard. Work part-time in the office of a primary school, babysitting.
Work experience: Oxford University Press, Literary Agent, Blenheim Palace (each for 1 week)
School/Academic Prizes: Commendation in British Physics Challenge, 1xGold and 2xSilver awards in British Maths Challenge, School Headmistress's award for endevour in years 7, 8, 9 (until they changed the rules and I can't get them anymore lol!), School prize for Academia in years 8 and 10.
Um, what else do they ask you? Does it matter what your parents do, if it helps then my father is an Oxford Don and my mother is a physicist.
Anyhow, I was just wondering whether it is worth (seriously) me having a go at the Ivy League, considering that there are so many people who are absolutely amazing who try. I know like grades/ECs aren't everything, and there's essays and forms and SATs and all, but what do you (honestly please) think?
Thanks! All your help is appreciated! Monty xxx