My daughter is a grade 10 and top student (1 over 75) of an international school (British system), she got TOEFL iBT > 100, however, SSAT around 50% without any preparation for all the exam. She has got immediate admission after interview from Bryn Mawr, Ashley Hall, Maumee Valley day schools with open choice either Grade 10 or 11. Of course school advices for Grade 10 for her to have more time for preparation and transition. To cope daughter's aim for US top 10 universities, I would appreciate if you could kindly advice if it is worth and feasible for her to try Grade 11, especially she is a quite disciplined and diligent student, as we hope not to spend additional year for her to repeat Grade 10 but has concern if it will be difficult to achieve the objective.
I can feel that your child is an excellent student! Now you must choose which way is the best way to prepare your child to get accepted to Top 10 universities, either by graduating from an international school here in China or by graduating from an American school.
Honestly, either way, your child will have to work so hard since getting an admission from top 10 universities, especially as a Chinese international student, would be terribly hard.
Becoming 11th grader at American high school would also be very risky because international students tend to suffer with their grades in their first year at a new American school, and grades as 11th would be considered as the most significant ones that show student's intelligence, rigor, willingness and focus by many top universities. Schools that know this usually recommends international students to lower one grade down.
Also there is a good chance for your child to get accepted to one of top universities while your child stays at a current school. Your child should have a very careful college application plan, starting now! Please find someone who can give advice in this matter. These professionals might help you greatly. So, choice is yours!