I think the best thing to do is what you are doing. Detaching from the quacking is the only way to stay sane. This woman at work is not performing up to par, so she needs to be replaced. If your sister is not physically putting any effort into your relationship, then it's okay to back off and not try to shove anything down her throat. If your H is content just 'wanting things to change' as opposed to taking part in the process, well that just sounds like procrastination. I mean, he can't come out and say "i don't want to work on this relationship" because you'd leave i'm guessing, so as long as he tells you he wants to, he's safe for now? People who tell me they are working on personal issues, and don't show any signs of action, are usually just saying it to pacify me. Just my experience with my ex, and a few others.
Them: i'm working on keeping my station clean during service.
Me: there's **** all over your table, you're cutting board has meat juices all over it, and there's chopped parsley garnish everywhere.
Them: well i want to work on keeping my station clean during service.
Me: If you wanted to work on it, there wouldn't be parsley everywhere, you would wipe off your cutting board after you sliced and plated that steak, fold up your service towels, and be ready for the next order. Instead of telling me you want to do something, just do it.
I think it's common for people to talk a big talk, and not walk the walk. I see it all the time. I used to go to an offleash dog park in NC, and i'd hear people saying "so and so's dog is digging all these holes and the owner isn't filling them, someone should say something", or "that guy's dog is being aggressive, and he isn't leaving, that's just not right, someone should say something'. Guess who was the only one to say something? Damn straight. Me.
People are content to complain about something, but won't take the initiative to contribute to the solution. Sometimes it's just more fun to complain. They get satisfaction out of it. Acknowledging there is a problem, and waiting for someone else to solve the problem. Like acknowledgment was such a tough job, thank goodness you pointed it out to me, your work is done here, I'll take care of the rest.
Maybe I'm just babbling here, i don't know if that makes any sense.