Polycystic Ovary Syndrome. There is a sub-forum for the topic under General Health.
Your mum has gone through a number of stresses to her body at once. As Nancy wrote, any change in diet, be it low calorie or low carb, can cause some hair loss. Plus the new drug. All stresses so don't be surprised if there is no one deficient nutrient. Just keep up the protein and good fats, biotin helps some people. Dr. Michael Eades blog had a good explanation of the process.
http://www.proteinpower.com/drmike/...ss-and-kimkins/