Hi Sweetmelissa
Stress is indeed often a trigger for people with BPD. When I look at my own uBPD mom and sis, big events such as holidays, birthdays and vacations often bring out the worst in them.
People with BPD are also often very sensitive with high validation needs. As a result they might be easily offended or perceive innocuous comments and events as huge slights.
Another thing that comes to mind is the intense fear of abandonment many people with BPD have.
Do you perhaps feels that any of these things also apply to your sister?
I think it has to do with her looking at her life as she is getting older and not liking what she sees. Any thoughts?
Has your sister ever said anything about or perhaps hinted at looking back at her life and not liking what she sees?