Would you use herbs with an anorexic?

Yes, in most case I would most definitely use herbs. They may be the difference between her pulling out of this or not. You could of course accomplish all of this with acupuncture as well, but it would have to be consistent treatment. The herbs can help stabilize the strength of the body and the blood fairly quickly and arguably safer than many other approaches. You of course have to ensure that she is both receiving counseling and regular medical checkups and blood work as well.

While you have to consider the anorexia of course, you primarily need to throw out all of those western concepts - “insomnia” and “anorexia” and treat what you see. So derive her proper Chinese Medicine diagnosis and use whatever means appropriate to treat that and you will likely do well. More than likely you would want some qi and blood tonification, -possibly- a formula like gui pi wan - or some combination of bu zhong yi qi wan with tian wan bu xin wan (to benefit the heart, palptiations, insomnia). But, again, it is absolutely critical that you do not try to treat symptoms/conditions but her Chinese Medicine diagnosis. Also keep in mind that the insomnia and anorexia and similar parts of the brain so even from a western perspective you cannot really separate the two from the overall whole person.