Good points from everyone here. If you want to wake here up to TTATT, how about suggesting that you go through doctrines unique to Jehovah's Witnesses and prove them scripturally. Say: "I think we think we know our Bible pretty well. If that's the case, we can prove all our doctrines scripturally without the use of the any WT publications. So, let's do that. Let's pretend we have to defend our beliefs to a householder."
You might even suggest that each week, for the WT study, that you go through each of the cited scriptures and read them in context to see if they really say what the WT says they say. You could start with this past weekend's WT that cites Phil 3:15,16. Then read that in context (esp. verses 13,14) to see what Paul was really saying. Then, the best thing to do would be to actually look up the scripture in the indexes (use the WT Library, but use the indexes) to see every place the verse(s) are cited and read what the WT has to say about the verse. Does it match what the Bible says? I can tell you that this is an eye-opening exercise. This is one way that I learned TTATT.
Oh, and really important: keep a notebook together of topics discussed and verses involved. It's easy to forget things. The WT may say use a scripture that will make her go, 'see, this proves it', but you'll have other verses that say otherwise.
The hard part will be to get past the "in a sense", "evidently", "logically, then" wiggle words that has been used for decades.
