<blockquote><b>Quoting crazy coupon lady:</b>" Its actually normal up to the age of 6 yrs old. After 6 if it still happens a lot, they usually set up an evaluation to assess why its still happening. At least they do it like that here."</blockquote>
It depends on why they're doing it. Most kids can write correctly. They just write backwards out of boredom. But it is normal until usually first or second grade to see letters backwards. That's why a lot of kids will mess up p's and q's and b's and d's for quite some time.