Well, as far as I know borderline personality is life-long and manifests itself in the teen years. My mother never exhibited these symptoms before. There were occasional fights, but not this bad. She never had suicidal ideation, she was a very good mother and a successful professional. This doesn't fit with borderline.
Narcissistic personality is also life-long. Her problems, on the other hand, started 10-15 years ago, initially very mild, with occasional irritability, and progressed to this. This seems to be a lot more acute.
P.S. There are no serious objective stressors in her life. Her chief compain in "You two (my father and I) ruined my life." There are no specifics, nothing she would like us to do other than "get out of my life". She seems to get better immediately after fights if everyone esle fights back. Lately this "good time" has been getting shorter and shorter, down to only a few hours. If we avoid the fight or stay calm she will continue for days, will cry for days, call everyone she knows and tell them what an aweful family she has. She still goes to work. Today she left the house and said she is leaving us. I feel no amount of talking to her does any good, and she refuses to see a doctor.