I'm sure she has eaten in 14 days. Maybe not solids or maybe not a lot, but something or else she'd not be conscious. And at BMI 10 she should be in intensive care in hospital, or dead. I think you're mistaken because at BMI 10 she would not be able to walk or even sit up in bed and she'd probably be dead. Some of the most severe anorexics in history were BMI 12. So I'm sure you're mistaken but either way, if she really is that small her parents can admit her to inpatient regardless of what she says because they can claim she is not of fit mind to make her own decisions. But what you can do is support her, tell her how much you love her everyday and how you'll never leave her no matter what, stuff like that. You can't force her to start believing she deserves vitality and life, because anorexic don't think that way. We think we are the most vile, worthless, disappointing pieces of **** on the planet and deserve nothing. That's why we don't eat. We like how it hurts because we think we deserve that. If she is anorexic she has either had a very traumatic past or is just severely depressed or mentally ill (borderline personality disorder?) So she needs to continue working hard with her therapist to conquer these issues and manage her ED. There is no such thing as getting over anorexia. It is a lifelong condition, you just learn to manage it. It has been with her her whole life too. Studies have shown that anorexics have scanable differences in their brains and that they exhibit symptoms from an early age, even if the disease doesn't set in til adult hood. For example, I first startled myself and puked myself at age 7, and said I wanted to commit suicide at 8.
How old is she? Is she old enough for her parents to admit her to help her?
If she is older and not willing to go then you can't really do anything but encourage her and tell her how beautiful she is. However most of the time someone dealing with self harm has other issues that she is mentally dealing with.
Best thing to do is try to get her to see a therapist that deals with eating disorders.
This is hard I can imagine but she is hurting inside and that is why she is doing this to herself. She doesn't lover herself and usually there is a reason