Yeah, I do sometimes feel bummed that evil people won't get what's coming to them and good people won't get do overs. That's a tough one to get over.
I don't have any miraculous words of wisdom to help people get over it, either.
At some level they understand the reality that the world's a rough place, that might be what drew them in or kept them in the religion with its hopes of righting wrongs and making everything right one day.
But, now they have to sit with the fact that the world's a rough place and it's up to them to make the best of it. You live once and that's it. In some ways that's comforting because that leaves the effort to have a good life in your own hands and that's now allowable, unlike living life under the JW regime.
I'm sure your relatives can see that you've created a decent life for yourself so that means it is possible for them, too.