I think the first step is diagnosis. Your daughter's condition will dictate your approach.
Question 1: Has she accepted the idea that this is a divinely appointed organization.
If she has accepted that, she is for all intents and purposes a witness. You must treat her and approach her in that way. That is a discussion far to complex for the scope of this thread... maybe even this forum.
If she has not, you must inoculate her to that idea. The best way to do that is produce items that damages the wt credibility... which isn't very hard.
Why not ask her straight up, "On a scale from one to ten, how convinced are you that this is God' only, one true, organization?"
Sorry if you already know the above... and I am very sorry if she has full blown JW-itis.
And yes, the method of getting compliance out of people by offering them something is tried and true.
There are 6 methods of influence used by compliance professionals identified by Robert Cialdini in his book Influence: The Principles of Persuasion.
1. Social Proof - Other people are doing it, so it must be the right thing.
2. Liking - I like them, so I will do what they want.
3. Commitment and Consistency - I agreed to do that, so I must agree to do this to be consistent.
4. Reciprocity - They did this for me, so now I feel obligated to comply.
5. Authority - They appear to be authoritative, so I will do what they want.
6. Scarcity - This opportunity is going away, so I better get it now!!!
Actually the dubs use all of these in some ways. They use reciprocity in many ways, "free Bible study", "free publications", all these nice folks trying to do you favors and wanting to be your friend all of a sudden. The real sneaky part of the reciprocity rule is it allows the compliance professional to set the terms. They offer something, which is accepted, and then at a later time they make a request that is far beyond what was given. But the individual feels obligated, so they give in.
Maybe present that idea itself in a neutral setting. Tell her how some salesperson offered you a free sample. Then later on they started making you feel guilty for not wanting to buy their product. Ask her what she thinks about that? Ask her what she thinks a person should do in that situation? Ask her if she thinks a person should feel obligated when someone gives us something to get us to agree to something else?