I understand your concerns! However, transferring to another school, especially academically strong one in USA, would be a great challenge to a student and even family. Typically, junior year (11th) would be the toughest and most challenging year for a high school students because a student must maintain high GPA, excellent extra-activities, high scores from tests such as SAT 1, SAT subject test (if colleges require), or TOEFL. Without proper preparations, a student usually suffers a lot, especially in the junior year even to an excellent American student.
Also, definitely, it is too late to get accepted to a good school at this time. All good schools have already registered new students and this is time to prepare a new school season. If there is a space available at the school, you might want to do your own research on that school before you go to the school (please check whether school is a better school or not in terms of sending its graduates to some of best colleges and universities than your current school)
My sincere advice for you if you aim to one of top 30 liberal arts colleges (I really admire you are considering liberal arts colleges!!) is to find someone who can guide you in the process of college applications and give you effective counseling to you in order to accomplish your goal. You might still have a good chance especially if you try to liberal art colleges while you stay in your current school!
如果你孩子数理基础不错,欢迎和我联系。
我们学校的特点是学生数理成绩不错,ACT数学平均成绩30分。我们学校是IB学校,明年可供十一年级选择的数理高端课程和其他主课包括
IB math SL year 1/AP Calculus AB;
IB math HL year 1/AP Calculus BC;
IB math HL year 2;
IB physics HL year 1/AP Physics C;
IB chemistry HL year 1;
IB biology HL year 1;
IB arts HL year 1;
IB english HL year 1;
IB spanish HL year 1;
IB french HL year 1
。。。