Some kids can, some can't--even if they're both bright and will be very good readers by grade 3.
DS1 was highly verbal at a very, very young age. She could not read by K. She was kind of haltingly reading by end of K. That summer, something happened, and by the time she turned 6 (end of August), she was doing pretty well. She's now in the "top" reading group in her 1st grade classroom.
But her math is atrocious! (I was slow to take off with math, too. I do lots of quantitative work now, though... I feel comfortable with a long, slow simmer. No pressure.)