Hello to you.
You are right to be concerned. Jehovah’s Witnesses are a high control cult, the leadership is continuously grooming its members to dedicate their lives to the group and seeks to manipulate each and every aspect of a members life to achieve this.
The group uses personal ‘bible studies’, magazines, books, meetings, videos and so on to indoctrinate/brainwash individuals. Within this cult indoctrination material the group use the FOG model. Narcissistically using fear, obligation and guilt to to achieve its ends- to control the life of a person, ruthlessly breaking up families if necessary.
It’s a difficult job you have on your hands since love can be blind. But you must forewarn your daughter of the dangers of JWs. JWfacts.com is a good place to start.