That things will be always be like this with their family, that they will always be JW, that they will never change, that they will never have doubts or at least doubts that they will act on until the day they die? If so, how? Does it still make you very sad? Do you think you'll always be sad about it? Are you still angry? How do you deal with it?
Slightly different to you in that my family don't have anything to do with me so I don't have the frustration of getting preached at. Yes it makes me sad that they will probably die in that religion.
Occasionally I remember something from when we were kids and I feel sad but then I think they're not those people anymore, your life choices change you. My sister saving a bird that had been hurt and being so sad when it died. Where is that little girl? Subsumed by the cult monster religion.
I deal with it by just enjoying my life. I'm here if they want to leave. You can't stay sad or angry the whole time, it's a waste if life.