I read 1984 when I was 12. I got it’s intended message. I had the general feeling that “Social Studies” was flaky or fuzzy at best. When I read “Free to Choose” by Milton Friedman at age 16 things really crystallized for me. For the first time I found something about human activity that really clicked and seemed reasonable. I also learned that to master some subjects you had to do so in spite of the wishes of my overlords at the State Indoctrination Camps. (Otherwise known as California Public Schools).
I read 1984 when I was 12. I got it’s intended message.
I read the book at right around the same age, shortly before turning 12. I'd heard a little about the book by that age, enough to have understood that this book is Important. It was in the school library (I'd just started attending a middle school--grades 6 to 8, around ages 11 to 14). I checked out a copy and read it in my spare time (and not for any school assignment or other obligation).
At the very least, I didn't misinterpret the book as the author's daughter did. I also didn't have too much difficulty reading the parts from "The Theory and Practice of Oligarchical Collectivism."
I wouldn't recommend the book to most 12-year-olds, but neither would I withhold it entirely.
Is the 12-year-old in question even literate and intelligent enough to understand the book, interested and intellectually curious enough to complete it without too much duress, or mature enough to be reading about what Winston and Julia are doing?
(Not long before my time, 6th-graders in my part of the district were in elementary schools, not in middle schools. I have a hard time imagining finding 1984 in my elementary school.)