The change reflects the way the organisation has developed with two-thirds of its 240 member schools admitting girls. The HMC - it is keeping its old acronym - already has three women members and Priscilla Chadwick, newly appointed head of both Birkhamsted School and Birkhamsted School for Girls, is likely to become the fourth.
Gwen Randall, head of Framlingham College, Suffolk, in September 1993, was the first woman member of the HMC. She has been followed by Alison Willcocks of Bedales in Hampshire and Helen Williams at the Royal National Institute for the Blind New College, Worcester.
* Most 10-year-old girls have the final say in choosing a single-sex school, according to a survey carried out on behalf of the Girls' Public Day School Trust.
Their main reason for selecting a particular school was friendliness, although a third said the academic record was the deciding factor.
More than 80 per cent of parents rated a school for its reputation in the area and 70 per cent wanted a girls-only schools because they thought their daughter's exam results were likely to be better than at a mixed school.