Mary I know how frustrating it must be for you. You must so want to show your love for her by touching her, then you get slashed for your efforts. At her age it might be so ingrained in her not to appreciate stroking, that you might just have to resort to the look and don't touch approach. She is jolly lucky at her age to get such a wonderful understanding person to take her on. A lot of people would have returned her. People like to be liked. On the farm people started feeding the abandoned farm cat. But they got huffy and refused to feed her after she slashed them. I feed her and tell myself what right have I to expect her to show gratitude. But then I have got six wonderful cuddly cats to go home to. You have just got Kitty. You could perhaps get a feather duster, or similar to just touch her with so she gets used to being touched. And you don't get slashed. When she tolerates the stroking with a feather duster, or glove on a stick, she could be rewarded with a treat. But at the end of the day, it doesn't matter how much we love our cats, we have to respect that they don't have to return the adoration.
Julie.