I may or may not BU, but need a bit of a vent.
Dad is in his 90s. He suffers from Parkinson's. This year has seen a real decline in both his mobility and in his mental alertness. He struggles to hold a conversation for as much as an hour, and loses track of what he wants to say and the words to say it.
I have a half sister (DSis) and half brother (DBro). They are themselves in their 60s. They used to be close(ish) to dad, but since they started their own families (now 25-30 years ago) became less so, and for most of those years have seen him maybe once a year with a few letters and telephone calls in between. No major fallings out or reasons for low contact, just geographical distance, and business with independent lives. I am the only child from dad's second marriage, which happened when DSis and DBro were in their late teens/early 20s and the first marriage had broken down years previously. My mum still and dad are still together, and she is in effect now his full-time carer.
DM wrote to DSis and DBro to let them know that dad is deteriorating, and to suggest that if they want to hold conversations with him that they don't leave it too long before their next visit. Due to a history of them not doing so, she asked that they give her a week's notice of when they intend to come, and that they try their best to arrive at roughly the time they had indicated. There is a significant history of this not happening, which causes dad a lot of stress (anxiety being an effect of Parkinson's) and mum problems in catering (they live very rurally, and the nearest shops are 20 mins drive away - mum can't always leave dad if he is having a bad day so has to go shopping on the day he has a carer in or when he is having a better day).
DM also included in her update on dad's condition some advice about how to make the most of speaking with dad (speak slowly and facing him as despite his hearing aids he relies quite a lot on lipreading, if he is trying to find the words to reply to a question, just sit and let him do so without prompting, don't jump around in topics of conversation as he can't follow sudden changes).
DBro is coming to see dad in about a month - the first arrangement had to be cancelled because his wife has a party to go to, and of course they can only come on a Saturday because they work during the week and have to go to church on Sundays.
DSis replied to say that she won't be coming, as her "chaotic lifestyle" doesn't fit with DM's "rigid requirements". But that's ok, as she will see dad in heaven.
AIBU to be rather sickened by Dsis' attitude and think she is a selfish cow, and to think little better of DBro for prioritising parties and church over an ailing father?