If she insists that the bible is referring to the Watchtower Society ask her to prove it.
Why was the WTS chosen in 1919?
What unique teachings were they disseminating in 1919, that are still considered truth today?
What did Russel really say would happen in 1914? If she she's says that he predicted that Christ would come invisibly ask what happened in 1878?
If she can't prove that the WTS was chosen as god's channel of salvation, it doesn't matter what the bible says, it is irrelavant to her argument.