Painful birth for royal succession changes Expecting a royal heir: Kate Middleton. Australia is likely to fail to pass legislation recognising the right of a first-born female to ascend the British throne in time for the birth of the Duke and Duchess of Cambridge's first child, which gossip magazines have tipped to be a girl. Despite the Queen requesting the changes to the succession law in 2011 at the Commonwealth Heads of Government Meeting in Perth, it appears Federal Parliament will be unable to pass the bill before it rises for winter this month. The baby is due in July. The bill modernises a succession law dating back to 1701, which favoured younger sons over first-born daughters, and prohibited an heir from marrying a Catholic. The British Parliament passed the bill in April, but it cannot come into effect until all 16 Commonwealth nations have passed mirror legislation. In turn, the federal government cannot introduce the legislation until all Australian states have passed it. Only Queensland has passed its version of the bill, while the NSW upper house will debate the bill when it next sits in the last fortnight of this month. A spokesman for the South Australian Attorney-General John Rau said it expected to introduce the bill "before the end of the year." New Zealand was responsible for organising the Commonwealth law changes. The secretary of its department of Prime Minister and Cabinet, Rebecca Kitteridge, said only Britain and Canada had passed the legislation. But she said the law could be retrospectively applied.