Hi LovesRose
Welcome to the bpdfamily, all of us here are dealing with our BPD children who often cause us so much pain and grief despite how much we love and care for them. I commend you on recognising her suffering while you are hurting, great insight. It is most particularly difficult when there are grandchildren involved and I can totally relate to how you must be feeling.
My DD27 cut me off a few months ago after a violent rage/verbal abuse and left our state to go back to our home town with my GD1 to live with her father. I've had no contact since.
I've found wonderful people here who have encouraged my learning of BPD; as you suggest below you are already researching which is great credit to you.

There are also many resources available here for you to engage in at your own pace. It's also great to speak with others who can really relate to what you are going through.
How old is your daughter? Do you have people/friends around that can also support you?
Take care of yourself, our own mental health is also very important in being able to weather the storms of BPD. Keep coming here and sharing your story, we are here to help. Merlot :-)