I think we all read & respond to posts on here through the filter of our own experience (and can't convey tone); I saw the OP as something very like the kind of thing my mother would say, which would annoy me, and I would pull her up on it. But of course we know nothing about the characters of the OP and her MiL, if there's history of this sort of thing being an issue etc etc.
Yes, I do see what you mean. With my mother I tend to gently get out of her what is going on because the problem is usually miss communication rather than anything and she would be bothered if she thought I could assume her intentions were mean spirited. She usually gets in a tiss trying to do the right thing iyswim.