OP I'm sorry you've got so much to be dealing with and all on your shoulders too since your siblings don't seem very involved. Must be difficult when you're so ill yourself. There's some further practical things to consider though.
Your mum can go to a care home in your area but I don't know if the hospital/social services will organise that, they might only organise for one in her area. If you find one in your area where you want her to go you can tell them. Then they can pass her onto social services in your area who can organise it. You can also attend the 8am meeting if you want, you have a right to be there if you want to have your say about it all, but if you don't want to that's fine too.
Since your mum is definitely dying and they've confirmed it now, have you given any thought to her house/flat? Does she own it or is it rented? If she claims housing benefit that will stop when she goes to a care home so the place would need to be emptied and given back to the landlord. If you've any time and ability to do it, it might be worth it to start the clearing out now so it doesn't all have to be done all at once, whilst you're grieving. If she owns it there's less of a hurry. Just check with her so you don't accidentally get rid of something that she intends to leave to someone in her will.
Your mum will probably want some of her favourite things to go with her to the care home anyway, plus toiletries and clothes.
Has your mum made a will? As long as she's of sound mind she still has time to make one now if she wants. If she's already done it, it's helpful if she can tell you where it is.
Do you know what her wishes are for a funeral ie cremation or burial? And whether she has the funds to pay for it. There's grants available if she/you doesn't have money to pay for it. If she owns a house the money for the funeral can come out of the sale of that.
It might be that you don't have the sort of relationship where you can have these conversations with her, but it's helpful for afterwards if you can.
It's better eg to know that documents for a funeral plan are in the top drawer of her desk, instead of having to search the whole house for documents that maybe don't even exist because you've no idea if she has a funeral plan or not.