blisterfeet, I feel for you. Sorry to hear about your father.
However, as far as the relationship goes with the JW family, all you can do is make yourself available. It's up to them what relationships they have, or not. Lifelong JWs tend to be rather childish, so it's hard to know how they react. Perhaps this is because even though they say that they have faith they will "fall asleep in death" and then wake up in the new system, disease free, they don't really believe it. Panic sets in, just as it can with anyone else.
But I think you can be at peace knowing you were willing to be with them, and the "ball was in their court".