Slng - I think all schools sent that letter out this week - is it the one with the rather awful line drawings of "a nit" and " a louse"?
Don't want to teach you to suck eggs (or nits LOL) but the most effective way to de-louse is to massage any conditioner into the hair and then carefully comb through with the nit comb once a week.
None of the chemical shampoos work effectively
There was a louse epedemic in the DS1's class last winter and it took months to get rid of, as one girl remained untreated. It was only when parents started to complain and the Head rang the girl's (semi famous) mother that she was treated and they dies out. Her head literally crawled with the buggers and you could see them wandering around on her head. DS1 sat next to her at school for an entire term and got infected daily so I had to delouse him and DD every night
SFRX - the tumour has apprently stopped growing suddenly so we are just hoping they can remove it - it must be so awful for her parents