Hubby and I learned TTATT at about age 60. At about the same time both of our 2ndgen JW widowed mothers needed our care. (both of us are only children).
We kept what we learned from my mother who was in her mid-90s and suffered from dementia. Telling her anything contrary to her religion would be pointless. However, Hubby's mother was in her mid-80's and still sharp at the time so we s.l.o.w.l.y shared certain doubts, questions, and experiences with her. we were always calm- sort of matter-of-fact like it was no big deal.
We could tell it was having an effect. At the point where we had to move in together, we noticed that she quit contributing. Then she stopped asking to be taken to the KH for meetings. Next, she quit the phone tie-in. On meeting nights I made her favorite cocktail, fluffed the pillows of her easy chair, and watched her favorite TV show with her. She never said it out loud but she no longer was a believer. Shortly after she moved in she passed away peacefully. For her, learning TTATT freed her from any F.O.G. I only wish we had figured things out so much sooner!