It's always difficult to know what to do in these situations, respond too much and you might just encourage it to increase in the future, respond too little and you risk the worst case scenario. It's a balancing act - and ultimately you know her better than any of us do, so the ultimate call has to be yours to make.
Are her parents involved in this "dispute" at all, or is she just trying to leverage against you? Could she be "distracted" by something shiny that makes her happy for a couple days and she forgets all about what's distressing her right now? (Some pwBPDs are very easy to distract, others are not - one of the few metrics on which I'm on the lucky side). Suicide threats and attempts are remarkably high amongst pwBPDs as I'm sure you know - but they are only rarely successful. Over their entire lifetime, I believe the number is 8-12% will eventually kill themselves - but it's not as scary as it immediately sounds because unlike the general population, nearly all pwBPDs will have threatened it or attempted it - so the presence of a threat/plan/attempt is not quite as drastic as when it occurs in a "healthy person". (Obviously we're using skewed definitions of healthy here)
