I am currently a junior in NYC. I received a 35 on my ACT, and have a 92 overall average (5 semesters in total). My average last semester was a 96, but freshman and sophomore year, was a 91. I got diagnosed with ADHD this year, and as soon as I started medication, my average went up from a 93 mid-year to a 96. I'm taking 3 APs this year and took one last year. What are my chances of getting into Columbia, considering I have double legacy and a parent who works there (especially taking into account the trend in grades)? Thank you!
Based on the information you've provided, your chances seem decent. Your ACT score is above average for Columbia's admitted students (the average is a 33), and your unweighted GPA is close to a 4.0 even with your slightly lower grades freshman and sophomore years. While Columbia doesn't release information on their acceptance rate for legacy students, they do mention on their website that legacies have a slight advantage if their qualifications are comparable to those of other candidates.
That being said, there are a lot of things I don't know about your course record. Columbia will expect you to have taken the most difficult classes throughout all four years, so your odds would be less promising if you earned some of your high grades in less challenging courses. Another important area that you don't give details about is extracurriculars. Since Columbia is so ridiculously selective, they're looking for students who have impressive outside achievements to go along with stellar grades and test scores. There are many high schoolers with great ACT scores and grades in the A range, but most of them won't be admitted to schools like Columbia if they don't have that extra special something.
The bottom line is that Columbia seems like a pretty realistic goal for you, but you may want to do a little more work to make yourself stand out from the crowd of other superficially qualified applicants.