It's fair to say 'I don't want to talk about it today, if I find out anything new, you'll be the first to know.'
Good on you for engaging with her for this long. I don't have the patience which is why a few super needy people got the flick when I felt that every conversation was an exhausting pity fest. It's really hard when you know they are having a tough time, but the old saying 'misery loves company' springs to mind--some folk just love to roll in misfortune like dogs like to roll in dead rabbits. Not helpful when you just want to get away from the smell for a while. Mxx