What is acceptable to put in the Additional Information section?

I am Taiwanese-American. In Taiwan, many people speak Mandarin Chinese, but neither of my parents speak it (I did not learn any language besides English growing up); my father only knows the dialect in Taiwan. Not knowing Mandarin Chinese, I chose to take it in middle and high school out of my own interest, earning high grades in them every year (finished AP Chinese with an unweighted 100), and I was also admitted to my state’s very selective summer program for Mandarin Chinese last year. Despite my achievements in Chinese, I worry that college admissions officers will assume that I am a native speaker of Chinese based on my ethnicity, so would it be appropriate to mention that prior to middle school, my only language was English? Thank you!

Don’t worry, they won’t.

Thank you!