If you could tell us a little bit about her it might help.
I personally would tell any JW something like the following:
Whatever happens no matter how bad it gets is not going to be anything like what the Watchtower predicts and you'll be wasting your time being in it.
They used to say that the end times was between 1799 and 1914 and that 1914 was going to be the start of the Millennium with Armageddon being a 40 year period between 1874 and 1914. Then when that failed they started saying that 1914 was the beginning of the end and that the end would end within the lifetime of those who were then alive. Now they make some incomprehensible statement about 1914 and "overlapping generations".
Don't waste your future with people who can't understand what their future is going to be like.
Keep it simple and short otherwise she won't remember what you said later on. No point in trying to deluge her with information. It won't make a lasting impression to make more than two or three points. Just stick to that one and elaborate on it.