If I come across wittnesses who don't recognise me , I get the hypothetical story going.
"Hi I have a very good friend who is a Jehovah witness and he no longer talks to his 18 year old daughter " then ask? " have they heard of any in the JW church been baptised at 12yo , they answer yes , "then ask are they free to examine other religions at an age of maturity", as they swirm pin them down on the story of your friends daughter. Tell them the father shuns this girl based on a decision the child made when she was 12. Ask them if there church still practices this arrangement. Ask why the prodigal son didn't have a judicial inquiry.