My hair has never been my crowning glory but when I was terribly ill at the age of 21 and had loads of surgery, painful treatment and masses of medication, the only thing that made me cry was my hair falling out. I didn't lose all of it, but already fine, it went much, much thinner. So not quite bald. Fortunately for me, it grew back over time as I recovered from my illness.
Earlier this year (46 years later), I went through a very worrying and stressful patch in my life and my hair began to fall out in handfuls every time I combed it. I have, to some extent, sorted out the problems and my hair is not falling out in the same way.
It is a deeply distressing and upsetting experience, made even more so because it seems trivial compared with serious illness. The problem may not be long term, but if it is, I would suggest getting in touch with a first-class wig-maker – and then have quite a lot fun doing it.
Our hair is one of things that, rightly or not, helps us define our femininity and losing it is hugely distressing. (Of course, that doesn't mean it isn't hard for chaps, in spite of the frequency of male pattern baldness.) Loving support is what she needs.