Jo Brighouse's piece, "When sugar and spice aren't all things nice" (Professional, 11 October), made me thoughtful.
I taught in three girls' schools across a 30-year career, and was a deputy headteacher and a headteacher, so I certainly have this T-shirt. I think girls are wonderful and I loved teaching them and working with them. However, friendships are hugely important to them and they care deeply about what other girls think. When friendships go wrong they can take it very badly. It always concerns me if people trivialise "girly falling out" (and Ms Brighouse didn't do that).
I absolutely agree that the intensity of friendship between a pair of girls can be one of the problems. If one girl decides that she needs to extend her social circle, the other left behind can feel betrayed and abandoned. When girls want to be unkind to each other, those who have been in close friendships have access to a great deal of personal information that they can use to hurt.
The Girls' Schools Association has a very useful website (www.mydaughter.co.uk), which is helpful for parents and teachers of girls dealing with such issues.
Jill Berry, Former headteacher.