Does she ever say anything to you or get rude about your writing? If not it may just be one of her neurotic tics that she can't help. I do weird stuff too. Like whenever we go to bed at night I have to check all the door locks and whenever we go out I have to check that the stove is turned off. My husband can tell me he already checked those things but it doesn't matter I still gotta do it myself.....sometimes twice. It's irrational and neurotic but it's also automatic and I do it without thinking. Now someone changing your writing at work is a little different but I'm just suggesting that when you talk to her about it try to realize she may not be meaning to offend you so much as she might just have a neurotic tic about writing.