It’s always so gaddamn hard to lose a pet and you two did of course the right thing, straight from the beginning, feeding her and taking her in and then putting her to rest. Perhaps showed her human kindness for the first time and I think she appreciated it, otherwise she wouldn’t have stayed. And I would check Buff out, if only to let go of my worry, sure it doesn’t change the outcome, if Leukaemia is the case, but sometimes vets can be really reassuring.