There are many different types of aggression in cats, and your kitty may likley have multiple issues. It sounds like your kitty is showing some predatory aggression toward you by attacking your limbs. This is a dangerous situation, and one that is not easily corrected. It would be especially hard to change your cat's behavior, since she has done this for such a long time, and she is already 8 years-old. The best chance of correcting aggressive problems in cats is when they are very young.
Treatment of this problem in cats usually involves the following:
1. Owners can be taught to recognize signs of impending aggression. Signs can include tail
up and swiveled, staring, pupil dilation, head hunched, claws unsheathed, stillness, tenseness, standing up of the hairs on the back and tail, and sometimes a low growl. When any of these signs are noticed, all interaction should be stopped and the cat should be banished to another room away from people. The cat should be moved gently with a an object (like cardboard) or be enticed to follow a ping-pong ball or feather to the given area for banishment.
2. Completely avoiding any interaction between the cat and children. Anytime that your grandchildren or other children are around (boys or girls) the cat should be away in another room where no contact can take place.
3. The cat should wear a bell on its collar so that all people are warned when the cat is approaching. This avoids any chances of "sneak attacks".
4. Aggressive events can be interrupted with compressed air canisters or water pistols.
5. Provide activity/pkaytime where predatory behavior patterns can be targeted at appropriate toys. For example, you can encourage your kitty to stalk and chase a toy mouse or feather on a string that you pull and have control of (do not allow the kitty to play with the string by themselves).
6. You can also talk to your veterinarian about medications that can be prescribed, that could alter the cats aggressive behavior enough to make him a more agreeable pet again.
7. In some cases of extreme aggression, euthanasia is really the only option.
I am also attaching a client information handout that I use in my practice that discusses the many different types of aggression that can occur in cats. I hope that you find it useful.Click Here
I hope that this information is of some help to you. I know that this is a difficult situation for you.