What’s reasonable to expect from siblings?

[alladvicegratefullyappreciated]

I (youngest D of 3) live close to ailing DM (Alzheimer’s) and DF (cancer currently well controlled). Both 80. Carers x twice a day for DM. DM is early late stage so things are getting hard to manage. I cover a lot of appointments for DF as he can’t take DM with him. Plus see them at least for an afternoon each weekend. Work FT, 2 teenage DDs one Y11 both dance so lots of driving around in eves. DH getting very angry re input from DBs who live 2.5 hours away and come for a night about every 2 months. Both work FT and no kids. DH and I having arguments on repeat. What’s reasonable to expect of sibling contributions living further away?

I wanted to agree with the other posters who mentioned support for you. If you have stepped up and decided to be a carer, then your siblings have an obligation not to make things harder for you. That means deferring to your decisions, even if they disagree.

This happened with my mother and grandmother. She lived thousands of miles away and could not provide any real support so everything fell to her sister, my aunt. My mother was extremely unhappy with the end of life decisions aunt made. Mom didn’t say a word to aunt. Instead she called me for emotional support. She understood that her sister didn’t need that burden.

DH is the 'nearby' sibling in this scenario. Not so nearby that daily after-work visits don't take a large chunk of useful evening downtime. Early dinner, sort out necessary chores at home, then two hours on the FIL visit. Boom, most of the evening's gone. SIL lives a couple of hours away and visits most weekends, doing one overnight. I can't help but wonder if DH would do the same if their geographical locations were reversed. MIL and FIL never needed care simultaneously, so it's been a slog of several years with a brief few months where occasional weekends and evenings off were possible.
Point is that both of them think the other should be doing more, or different, things, and that their own respective contributions are the most significant. The sibling relationship has completely soured over the stress. They're in the process of organising care for FIL, and the one thing they agree on is that his wish to stay in his own home cannot continue to impinge on their freedom to live their own lives again. Or at least have a bit of a social life. The ILs were always very insistent on protecting theirs. You need to consider what you need from any arrangement, OP.

I decide what i do and leave my DBs to do what they decide to do
And my DH supports me totally

What you should expect is that when you say 'right, we need to start talking nursing homes' that they don't kick off 'no mother of mine will go into a home' etc) if they've never given any realistic support. If I were you I would start floating the idea now.

You may have been busier but plenty of people live busy lives without children. Just because you don’t have children doesn’t mean you have lots of spare time.

Do your parents have attendance allowance? Do they have discounted council tax? These things can fund extra care.
a useful thing is a family what’s app where you can share info.
And you cannot “make “ them do anything. A cancer diagnosis(mine) was what it took to get my dbs, all 1-1.5 hours away to commit to regular visits.

To be clear - I don’t want to ‘make’ DBs do anything. As PPs have pointed out it’s up to them what they do. What I am asking is whether it’s reasonable to ask as the whole issue has become quite emotive for me given feelings towards parents, DDs and DH as well as relationships with DB.

DF already gets attendance allowance for DM and pretty good support from SS. DF incredibly resistant to even contemplating a home …

I think it is very reasonable to point out that, yes, it is easier for you in one way, in terms of distance to give them support, but that you are currently giving that support 7 days a week, and, with your responsibilities to yourself, your dh and your dc, you can't sustain that. Then put forward the suggestion of each of them coming at the weekend once a fortnight would help immensely, if that is something they could arrange.
It will also give them some insight in to what the daily grind actually looks like, and they might come up with suggestions in terms of things they can practically do to help (batch cooking maybe, or some of the looking after the house, changing sheets etc etc.).

But if you cut back what you do will DF still be resistant to a home @alladvicegratefullyappreciated?

If you cut back -and you must- then cracks in the arrangements your DF reckons are ‘fine’ will appear very quickly.
OP, will do herself no favours if she continues to prop them up.
DF needs to be so sufficiently inconvenienced that he realises ‘help’ is required.