Yeah, there is certainly some truth to it. It will regrow, if she lets it. And for the colour: sooner or later its just the thing you do if you don't feel like grey hair. You dye it. I wonder if she has grey hair. In my family I seem to have two extremes. One grandma got grey hair in the middle of her twenties, the other when she was passed sixty. I haven't got any, yet. If I did, I am sure I'd dye them. Until I feel old enough for grey hair.
I got nothing, but my parents are genetic freaks as far as grey hair goes. I am pretty annoyed at how thin it's gotten suddenly though as I have never dyed it but whatever. There's nothing to be done about that.