No, no, no! Do not waste your time any further with this plan of attack. It's time for you to get sneaky. Seriously, you need a longterm plan to systematically undo the bonds of the cult. Please do yourself a huge favor and read Steven Hassan's two cult-help books "releasing the bonds: empowering people to think for themselves" and the other book by him (I can't remember the name of it at the moment).
You have to prep her carefully over time and be patient. I hate to say this, but you will have to be plotting out your moves very slowly and carefully including watching her body language, knowing what type of attachment she has to the group (emotional, phsyical etc) and what factors she feels are most important. seriously- please read those books. I really believe that having a well-planned attack is the best way to help get someone out...