I disagree about "correctness". I think it is a great advantage to kids to see a variety of people in books that have pictures. I know that studies support me on this.
Of course, when I was a 1st grader, a very long time ago, I looked something like "Sally" but I hated those books, probably because I was way past them when they were handed out. I also felt the dialog was really silly. I greatly prefer the current system of placing kids by skill level. I wished I'd dared act like my best friend's brother, who finished reading Fun with Dick and Jane while they were being passed out and loudly asked for a more interesting book.