My 12 Year Old Daughter Has Started Losing All Her

my 12 year old daughter has started losing all her hair. evenly over her scalp.she has lost about 60% in two weeks. her skin on her body is dry and red but not itchy. she has begun to sleep alot and i have checked her blood glucose it is noraml. she eats like three men at once. she heats healthy and not much junk food and maybe a couple of sodas a week so it's not malnutrtion. but i still don't know what causing all her hair to fall out