I'm not a teacher, am I?
I was just using your post because it was a handy example. My idea was that readers would say, "oh, yeah, I didn't notice that before - now I can see that this kind of correspondence is more common that I had thought. Maybe I was a little hard on the teacher."
And even if you're not a teacher, I have no doubt you'd be perfectly capable of teaching third-grade reading, despite what might be a less-than-perfect post.
I guess I'm just saying that, in my opinion, if it was my kid, I'd be glad that he had such an interested and involved teacher. If I thought she was truly incapable of teaching third-grade reading, well, I agree that would be another story.
Also, I wonder if people are aware that proofreading isn't always that easy, especially when you're proofreading your own writing. It's very easy not to see mistakes that are obvious to others.