I tell my patients that seeking holistic care is fine, but please adhere to traditional treatments at the same time.

There are plenty of "holistic" supplements that can benefit somebody undergoing cancer therapies.

Anti Cancer Living is the best book that I am aware of that looks at the benefit of diet, exercise, meditation, etc in the treatment of cancer.

I think she will really like this book. You should send her a copy or purchase the audible version for her.