Hi Koona
Welcome to bpdfamily, I'm sorry what brings you here, there are many grandparents and parents in your situation, who can provide you personal advice, you are not alone.
Stepping out of your DD's and her husbands drama and fear can help you makes changes, to the right

are tools and lessons, is a good step forward. We can't change them, we can show them the way through our change.
Has your DD been diagnosed BPD?
We are here for you, keep posting and let us know how we can help.
WDx