WT is so good in brain washing. Since she is going to their meetings the process of brainwashing works perfectly, especially the: us vs them mentality. Evil vs bad, God vs devil. You cannot oppose to her, since this it will cause the defense mechanism implant to her by the WT to act against you. I suggest to show her the flip flop doctrines of the WT and the fact that they have a short history as a group(sect)but with many failed prophesies.
Try to show her for instance how did WT viewed organ transplans in 1964(it was OK) the in 1967(became cannibalist act!)and in 1980 again it was ok!. So who is to blammed for all those thousands who died between 1967-1980? God's spirit or a man made organization?
Then you can point out that their founder Russell what he believed as "truth" for at least 60 years, now it is consider "apostate teachings". Even their founder it wouldn't have a place amongst modern day JW's.
I was raised in that evil cult. I left when I was 35 and this caused me to lost my entire family. Your daughter is in danger. What I'm afraid is that after she becomes a JW, the "system" will push her to get married a "faithful brother" and it will turn things even worsed. I know how they are acting since I was raised there. Specially when there is a new single person that joins their club, the next thing they do is to find a "faithful mate" so they will lock him/her at their organization.
If you need more help just ask us, you can send me a PM also if you like. No matter what you must act fast, since your daughter is in danger.