The situation is tragic, a person who suffers from a personality disorder is not able to live a normal life, and in a reported 87% of cases the disorder is caused at least in part through abuse inflicted on them as children.
Very little of what she said was the truth. Sometimes it would be a lie in that she would knowingly say something which was not true in order to achieve a specific result. This she would do to run a distortion campaign, or to avoid “getting into trouble” when she had done something to which somebody would take exception or which was illegal, like lying to somebody in a position of authority. She would also do this to achieve a sense of power, to get away with something she had done which wasn’t likely to get her into trouble; she would exaggerate her achievements, or claim that the achievements of others were hers.
She had constructed a fictitious condition, epilepsy, which would yield various benefits to her. I suspect this started when she was much younger and she felt it had to be perpetuated to avoid being caught out in a lie. She had been prescribed various medications by a psychiatrist, some of which medication is also often prescribed for epilepsy. While under normal circumstances it would be difficult to see the benefits of having something as debilitating and life threatening as epilepsy, the benefits of pretending to have epilepsy which she was able to gain are these; Probably the origin of the lie, and possibly the most important benefit was that epilepsy provides an alternative valid reason for the medications which doesn’t carry the stigma which being mentally ill does. Epilepsy allows her to illicit sympathy when she feels sympathy is something she can use to leverage either for a commercial benefit or for something less tangible such as being allowed to bring her dog, a golden retriever, into a restaurant or just to use as a bargaining chip. Bulimia will cause seizures when allowed to reach extreme levels, and epilepsy is also a convenient explanation for these seizures, which does not carry the stigma of mental illness.
She had constructed other frameworks also, used in distortion campaigns, against her father, her sister and her mother and anyone with whom she has or has had a close relationship. I suspect that frameworks make it easier to remember the lie, but also make it easier to purport the lie as a truth, a lie sounds more believable to others if one believes the lie to be true oneself. One example of such a distortion campaign and commensurate framework was something which one of her prior significant others had coined “The Knitting Circle”, in which she would discuss him with her mother and sister at times when he was not present and make accusations against him of things he had said or done, which in reality had not taken place, specifically so that they would think less of him. This she would use to illicit some benefit at some later stage, he would be more easily coerced into doing something, or paying for something if presented with a united front by all three of the family members.
We hear or read about compulsive lying, hopefully this give a little more insight into what that means from a practical point of view.
Here a link to an interesting article about BPD and compulsive lying: