I would be concerned, too. It's been only recently that I've cut certain people slack in this area. I've had to realize that not everybody takes to language the same way. I used to live for diagramming sentences, in two languages. I love spelling and grammar and etymology; it just MAKES PERFECT SENSE to me, so much so that I racked my brain trying to understand how it's not like this for EVERYBODY. Everybody is not wired the same, though. As first nature as it seems to be for me, I have to consider my history and my make-up. I come from a family of wordsmiths and critical thinkers. For fun, there were sports, but there were also word games and lots of reading. And Math, but that's a different subject. (To this day, I don't understand not reading and not playing Boggle and Scrabble. Aren't these staples in everybody's life?) Everything was a lesson, something fundamental that I could use forever. I was taught to learn and keep learning. My great great aunt would never let us get away with saying, "I don't know," in response to being asked why we had done something. She taught us that there is always a reason, and it was our job to know why we did whatever we did. Right now, I don't accept "I don't know" from people, especially other adults. (This makes my husband crazy.) When I write, I don't mind looking up a word to make sure that I use it exactly as I mean to. This combination made me a classroom dream...or nightmare, depending on the teacher.
I say all that to say that not everybody learns the same, and not everybody is taught the same, and not everybody's home environment is nurturing to this type of teaching. I do hold the bar a little higher for educators. If language skills are not their strength, then I would like to see them acknowledge that and work on it. I would like for them to refrain from saying things to the kids that they could pick up incorrectly. I don't think that this is too much to ask. I think that it should be part of their Continuing Education, since it affects communication. It bothers me that at the very top, this is thought of as "no big deal". It does hurt people. I think that we should not cut people slack just because the newsletter is not required. If it's that easy for someone (teacher) to misuse the language, then that someone needs to take every opportunity to practice so that it becomes second (or first?) nature to SAY IT RIGHT. If wrong rolls out better than right, then that's a problem, no matter how insignificant any one case might seem.
No student is too young to start hearing the right things; we already know that they are learning well before they even go to school. You're gonna have to make sure that you speak and spell well at home and correct her when she does not. Proof that home can outweigh the classroom--I was the kid correcting my teachers.