New Zealand has had two female Prime Ministers but other "western" democracies have only had one female top leader (if that).

It is not obvious who, if anyone, amongst the current generation of female British politicians would be a credible candidate for Prime Minister. The previous generation had vivid political figures like Thatcher, Barbara Castle and Shirley Williams, but the Blair babes (ghastly public relations framing from 1997) seem to have been drowned out at the court of Tony the Phony.