Tone-of-voice check, please - is this a reasonable way of telling my (very kind, well-meaning) sister to stop interfering in relations between our other sister and our brother? And to stop involving me in her interfering? None of us live in same country, btw, except the two who aren't getting on (to put it mildly!)...
re. [other sis] and [brother] - I don't think there's anything you can do. They are adults and it's up to them to sort their own problems out. That includes their problems with each other as well as their individual problems.
If it makes you feel better to ask them about each other - even though neither one ever says anything positive about the other - then go for it, but I'd rather you left me out if it, thanks. They don't get on, so I can't see the point in either trying to get them to "help" each other, or listening to them snipe about each other. I think I support them best by taking each of them at face value, you know, just talking to them and encouraging them to focus on what is working in their own lives.
For what it's worth, I've been emailing with [bro] lately and he doesn't sound anything like what [sis] says. I can't help remembering that when we visited, [sis] complained to you, me and [my dh] about what a grumpy bitch I was, when neither [my dh] nor I thought I was grumpy at all, so I personally would take what she says about [bro] with a large grain of salt.