It may very well be that your sister is a narcissist and is grooming you. She walked away with the Lion's share of your father's estate, did not even CARE that your other sister struggles and really should have gotten something too, even YOU know that. She showed you who she really is all those years ago.

I have been learning the HARDEST lessons of my life from my older sister. The things she chose to do and manipulated and gaslighted has been incredible. Stuff I honestly could never imagine doing, so I did not see it until it was too late to change it.

She wants you to remember her for reasons most genuinely don't even think about. You are going to be single, no children, you are older so who will you leave whatever is left of you to? (even if there will be nothing, she really doesn't know that)

Thats what they do, throw you crumbs like this. It's more for themselves and that rarely changes. And bringing up the past will be a waste of time too. It's always nice to get flowers, just enjoy them. If there is something at all left, leave it to the sister that struggles and works so very hard and should have gotten something of what your father left.