You did well by not telling her what you know. It is way better to keep your opinions to yourself and just ask a very occasional question, in such a way that she feels obligated to answer it, then very calmly and without being confrontational, make her explain any dishonesty she uses to weasel her way out of properly answering that question. Keep focussed on making her answer the question that you asked so that she can't morph it into some other question that she is more comfortable with.
Take it easy, softly, softly catchee monkey.