80% of this is pure attention-seeking.
The BPD thought pattern is much like the NPD thought pattern, that they are entitled to be wanted, that being wanted is survival, and that they are therefore betrayed if they aren't. Loyalty tests ensue. Awareness that they are causing their own abandonment is zero. It isn't worth it.
I suspect she's gotten into your head and you needed to vent. Understandable enough. The real question is why your father lets her live in the house.
The BPD thought pattern is much like the NPD thought pattern, that they are entitled to be wanted, that being wanted is survival, and that they are therefore betrayed if they aren't. Loyalty tests ensue. Awareness that they are causing their own abandonment is zero. It isn't worth it.
I suspect she's gotten into your head and you needed to vent. Understandable enough. The real question is why your father lets her live in the house.
Hidey-ho, RVFerinos!