I"m sorry to hear of this with Gigi. There appears to be both dangerous prey (predatory) behavior as well as a general aggression toward people. I'll post my synposis for both behaviors. Please take your time perusing them and then return to our conversation with further question or concerns.
The clues for predatory aggression are moving feet being bitten. Predation is a highly motivated and instinctive behavior for cats. The prognosis for complete resolution of this kind of behavior is generally quite poor. The innate response of the cat is to stalk, chase, and attack, and there might be a killing bite. When this behavior is directed toward family or other pet in the home it needs to be addressed.
The predatory instinct is very difficult to suppress so the best approach to management is to prevent her access to you at the computer. To avoid your and others being "prey" when you're walking, we need to substitute appropriate prey objects for her. Considerable time playing "bird on a string/pole" and chasing laser light should refocus her attention away from you. She might be trained to fetch a ball or toy mouse. Chasing a ping-pong ball can occupy a cat such as she and you might find catnip-containing "chase toys" in the pet store that may lessen her dependence on you as prey. Unfortunately, there's no quick fix for inappropriate prey behavior but the above should be helpful for you to at least ameliorate the problem.
I have advanced training in feline behavior and I need to preface my discussion by telling you that feline aggression toward the owner can be challenging to manage. Many cats display aggression toward their owners when displaying assertiveness. Cats that have this type of problem usually display a confident temperament. They exhibit assertive or status aggression by biting or threatening when the owner attempts to approach or handle them or to simply show their displeasure or anxiety with their place in the hierarchy in your home. The bite behavior may be an attempt to control these situations. Assertive displays, pushy attention-seeking behavior and attempts to control the environment by blocking access to doorways and refusing to be moved from perches or sleeping areas may also be displays of social status. One sign that might signify this type of aggression is aggression toward members of the household that a cat can control, avoiding aggression with family members that control the cat and do not routinely give in to its demands. The prognosis is guarded as these cats may be dangerous and the problem may have both innate (she may have been feral as a kitten) and learned components (she may not have been socialized prior to the important age of 7 weeks). Too many of my owners have ended up hospitalized due to cat bites. You must decide whether Gigi risk to you is warranted vis a vis attempting to manage her inappropriate behavior. If you're willing, management involves the following:
Make the situation safe - identify stimuli leading to aggression - avoid confrontation and any stimuli or interactions that elicit aggression - teach simple commands such as "come" or "sit" by using food lures whenever Gigi is receptive to food or play.
Withhold rewards unless earned - she should be taught to defer to you for any treats, affection or play. For instance, play, affection and treats should never be given on demand but can be given if she responds to a command. After a few weeks of teaching deference, she can be taught to accept stimuli that have triggered aggression. You would need to begin by performing a behavior that has triggered aggression in the past but in such a muted way that no aggression is elicited. If no undesirable behavior is exhibited, she is given a very tasty food reward or play. Onces he's conditioned to accept a mild level of the stimulus, the sessions can progress with stimuli that very gradually become stronger.
Punishment must be avoided but undesirable behavior can be interrupted with alarms or a can of compressed air. Care must be taken with this approach since some strong stimuli can make a cat more aroused and aggressive.
Uninhibited aggressive displays that appear impulsive, explosive or excessive may be reduced with psychotherapeutic drugs - SSRIs - such as paroxetine (Paxil) or fluoxetine (Prozac) - not hormones. I prefer not to prescribe these drugs for what, in essence, is normal behavior for many cats. Drugs, however, are an important resource for the determined owner.
As mentioned above, Gigi is a significant danger to you and others to whom you might rehome her. If you're highly motivated to keep her in your home, I would suggest your seeking council with a board certified veterinary behaviorist who will come to your home and examine the dynamics therein. Her vet should be able to refer you to such a specialist or you can find one here: www.dacvb.com. I like the idea of keeping her sequestered in a quiet and dimly lit room until her level of arousal abates or perhaps allowing her outside more - where she needn't socialize to an extent past that which she's amenable.