I just want to thank all of you for your helpful input. Thanks for taking the time to help someone you don't even know - you are all amazing! In the light of what you have said I am going to play it very carefully.
I now have another difficulty: Betty, my mother-in-law is now elderly and one of my wife's sisters, who is in her 40s has the educational age of a child. She lives with Betty, but when Betty dies she will need somewhere smaller to live, maybe sheltered accommodation, and to be near a relative who can keep an eye on her bills and so on. Betty asked me to be the executor of her estate and I am named as such in her will. We had intended to use some of the money from the estate to ensure that my sister-in-law is safe and looked after when the time comes, and we had thought of finding somewhere close to us in Sheffield. This was perfectly ok with my sister-in-law, but recently Betty has been saying that her daughter must continue to live in the area where her JW friends are. I suspect that she has discussed this with the JW elders or whatever they are and they have swayed her view. My sister-in-law would be open to any persuasion by the JWs to do anythingthey wanted in terms of door-knocking and helping to raise sympathy for their beliefs. This worries us greatly. From what you have said so far, I think the best thing would be to wait until Betty has died and deal with it then. I just hope that Betty doesn't try to change her will in any way to force her daughter to remain in the area after she has gone.
If you have any further advice I would be grateful, though it is great just vto be able to share these things with people who know what it's like from the inside so to speak.
Thanks once again for all your kind help.