Learn as much as you can about the history of this religion. They have predicted the end many times, yet still pretend that Armageddon is imminent. I was told I didn't need to go to college as I would not have time for a career in this system of things, I am sixty now, yet they are still saying the same thing.
I have repeated my story many times, so I won't go into that, but there is a section here on experiences, read a few of those (click on Home, then look for that sub heading).
This religion uses mind control, it's helpful to know what that is, check out howcultswork.com. As others have stated, do not pressure your friend, she has already been told that Satan will try to stop her from studying, so that will just make her more determined to keep on.
There is no one way to wake people up, it very much depends on the circumstances and the personality of the people involved. Asking questions is better than informing, and be very careful. Potential topics to discuss:
Most JWs do not know the Watchtower has paid out millions to settle child abuse claims and currently have a few multi million dollar judgements against them.
They also don't know that Charles Russel, the founder of the WTBTS took most of his chronology from another religion, and its based on a date for the fall of Jerusalem that is not supported by any reputable bible scholar. Russel taught that based on this chronology they were in the last days and Armageddon would come in 1914. When nothing happened, they changed to teaching that Christ returned invisibly and the last days started (not ended) in 1914. They said that Armageddon would come before the generation alive and old enough to understand these things passed away. When it became obvious that that generation was passing away, they changed it to say that "a generation" could be overlapping generations. To any rational, thinking person it's obvious that they are just making things up, but such is the power of cult mind control that they accept these ridiculous explanations, because they have been trained to accept anything the governing body tells them.
This religion practices shunning and any member who leaves for any reason will be shunned by family and friends. They say they only disfellowship in cases of serious wrongdoing, but that is not the truth. A person who leaves and says they no longer want to be known as a Jehovah's Witness will he shunned. A person who just stops attending and then later celebrates Christmas (or votes, gets divorced and remarried without cause, or serves in the military, or takes a blood transfusion) will he shunned, no matter how long ago they left. A person can be disfellowshipped for just about anything three elders agree on, there is no recourse, decisions are rarely overturned.
This religion breaks up families and ruins lives. Shunning is so painful that many JWs commit suicide, I knew of six who did so. You need to do whatever you ccan to keep your friend from joining this cult, but be very careful.