Family relative just found she has breast cancer and is refusing any type of treatment or medical intervention. She believes "God" will heal her. IMO there is nothing you can do to change a person's mind when it is made up about the treatment they choose (or not). You'll just end up frustrating yourself and making yourself ill. Short of having her declared legally incompetent and unable to make her own decisions it is what it is. My heart goes out to you and your Mom.