... She got what she wanted for a short time, became happy, and now the rug is ripped out from under her. ...
No, that would not be the case. By the time the pastor went back (
if he went back) to the NASB she would be well aware of his reasons. She might appreciate the fact that he had preached for a time out of the KJV for her sake (and at the same time proving he actually has no prejudice against the KJV).
... I'd talk with her, read some material (again), pray about it with her, but under no circumstances would I switch versions during our research period. I would make it clear that in the end I am going to do what I believe God is leading me to do. ...
If the pastor cannot sincerely consider the woman's position, he might as well shut her down immediately. There is no point in patronizing her by reading material with a predetermined outcome in mind. Here emerges an element that has been broadly missed during this thread: that other people very often play a significant role in our development.
Obviously, we owe a lot of our 'self' to our parents (family) and teachers (education); but also to authors, preachers, friends, and media. How do we form the majority of our beliefs (personal, political, theological)? I would say that it starts from the influence of other people (yes, we should check those ideas against Scripture). But for example, most people are led to Lord by another person or through a sermon; very few get saved in isolation (say, by sitting down alone and reading the Bible). So now, if the pastor sincerely considers preaching from the KJV, he MIGHT actually decide that he is being led by the Lord to preach from it!
Not because this lady 'forced' him, or that he succumbed to somebody else's will. Perhaps he is reminded of the KJV's elegance or whatever, but it is his (His) choice. This potentiality has been mostly (if not completely) ignored throughout the responses to my posts. This is a reason to be prepared to make a change: because God, through the initiation of another person, wants us to change.