Shattered Origins, I don't post here often but this made me come out of my silence.
I agree that you have to do something to put a stop to this madness. So, I'd like to offer a TECHNICAL SOLUTION to the problem. I don't know whether your husband or you have some technical skills or if you can ask a friend to do this for you.
There is a free DNS service (DNS is like a telephone book that helps your computer find different websites on the internet) that allows you to block dubious websites and you can include specific ones like jw.org.
This way, at least from your computers / tablets / cellphones at home that are connected to your router or WI-FI nobody will be able to go to that website.
The service is called openDNS and you can find it here: https://store.opendns.com/get/home-free
Another option, if you only have ONE family computer, would be to follow these instructions provided you use Windows on your computer.
I know it all sounds very technical, but it is actually not that complicated and once it is setup, it should work without problems. Obviously, if your mom is accessing jw.org on HER own phone without connecting to your WI-FI it won't work. But you could offer access to it, so that every time she walks into your house it connects to your wi-fi and your filtering kicks in.
I see this as another option you could use which would enforce whatever you want in terms of websites.
Just my 2 cents!
Vivalavida