I am really sorry that you and your girls are going through this. I notice that your previous posts run along the same theme as this one ... she refuses to get help, you are the enemy, she doesn't care about the impact of the kids.
I and my daughter are at the beginning of a divorce driven by my BP spouse. I am not dealing with all the same aspects you are, but can only tell you that sometimes the only thing you can do to stay sane is to let go.
In my opinion, if a person with BP refuses to get treatment, there is little to nothing that you can do to help the situation. If she is not a danger to herself or others, then she is free to act in whatever manner she likes, regardless of the incredible pain it causes others.
You wanted advice: Write her a letter letting her know how much you care for her and want her to be in your life once she gets treatment ... and then let go. If you stop trying to get back with her, get some help, and start moving on, she might, just might, start to realize what she is losing.
Take care of yourself, take care of your girls. Get counseling as needed. Find joys in your life with your children, discover the good things inside or yourself. As painful as the process is, eventually things start to get a little better.