I agree, VS. That does seem to be a perfectly sound case for claiming, unless there is something missing.
I don't see this as the same as people wanting to pass on money to children when in care. For one thing, wanting to be able to do something and defrauding the system in order to do it are two different things. For another, the funding system for people in care is manifestly unfair - as has already been said, if you save you pay and if you spend you get it free, which is indefensible, IMO. It should be funded for all who have paid in, and taxes should be raised to make this possible.
How much money is involved? *I know that it doesn't matter legally*; but all the same, if this woman has paid in all her life, and now needs benefits for whatever reason, it seems wrong that she can't benefit from an inheritance when she would be able to if she was working. If the sums are large, she should definitely declare it; but if it is just enough to allow a few treats, it seems unjust that she shouldn't be able to have them, as her father wanted.
Means testing keeps people down.