This is a difficult situation because as you have discovered, you can’t make someone get help if they don’t want it. From what you have described here, your friend does exhibit symptoms of Bipolar Disorder and does have family history, but she could also have a personality disorder, such as Borderline, which might make it even more difficult for her to see that she needs help.
The best that you can do is to continue to suggest that she get more help than she is getting. You could also give her very honest feedback that you are beginning to feel drained by the friendship and that in order for it to last, you hope she will seek help. You could stage an intervention of sorts by enlisting the help of her adult children or other friends or coworkers that might be willing to help. Finally, her doctor cannot give you information about her care but nothing is stopping you from giving her doctor information. You could call the office or even write a letter and just explain that you are a concerned friend and you want to share some observations. However, you don’t have to go to these lengths and no matter what route you choose, you have to understand that she may still not seek more treatment, and even if she does, she may continue a fairly self-destructive path.
All the best,
Dr. Holly Counts