I know you've witnessed your child use their or there when they meant they're. Or the other way around. The same goes for to, too and two. I've even see adults mix it up. Heck, I've even seen it in published books.
But that's understandable because they are some of the most misused words in the English language. Don't let your child suffer those mistakes. Let Queen Shinobi teach your child how to use those words properly.