Hey...
my younger sis(13) is worried about her hair falling out...what do i tell her?

i have no idea why shes scared of it... her hair is thin, naturally, but everytime i tell her to calm down about it, she says give me facts!!!!!!!! and the truth is..i have no idea about if it CAN happen-- so what i need is basic facts to tell her... ???

im pretty sure she looses the normal amount ...i know that she thinks shes loosing more because her hair is so long and when you loose 10 hairs it looks like 20...since her hair is over 30 inches. She doesnt loose too many when she combs her hair when its wet, or in the shower, but i think she says that she finds most of her hair on the back of her shirt of the course of the day...i keep telling her that it looks like more is falling out  than really is ... but most of the time shes just scared , and has no proof of hair loss --but again she want "facts"...