I've been dealing with this for 15 years. for FIFTEEN YEARS I haven't been able to stop yanking hair out of my head! I'm glad to see that there are so many others out there with the same struggle! It's caused me lots of pain and embarassment over the years. My hair dressers are always baffled when they go to cut my hair...
Also be aware that there are trichophages out there who EAT the hair they pull.
She could have Cushing's Disease, which causes people to gain weight primarily in their stomach, face, and in a "buffalo hump" on their back, while their arms and legs are usually a relatively normal size. It's caused by a pituitary tumor, and if she has it, she'll never be able to keep the weight off.
Also be aware that there are trichophages out there who EAT the hair they pull.