As the historic changes to the monarchy were agreed, the Queen, at the Commonwealth summit in Perth, Australia, hailed the power of women to change the world.
The reforms mean the if the Duke and Duchess of Cambridge's first child is a girl, she will take precedence over any younger brothers in the order of succession.
The 16 Commonwealth 'realms', including the UK, Canada and Australia, also agreed to scrap outdated laws which ban anyone in the line of succession from marrying a Roman Catholic.
The changes were announced by Prime Minister David Cameron at the Commonwealth Heads of Government Meeting in Perth.
As politicians unanimously agreed the dramatic reform to royal succession laws dating back more than 300 years, the Queen said the untapped potential of women and girls should be set free.
Speaking at the opening of the summit of the 53 Commonwealth countries, she said: 'The theme this year is Women As Agents of Change.
'It reminds us of the potential in our societies that is yet to be fully unlocked and it encourages us to find ways to allow all girls and women to play their full part.'
'We must continue to strive in our own countries and across the Commonwealth together to promote that theme in a lasting way beyond this year.'
Her comments will be taken as a sign that the Queen approves of the reform.
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The Queen makes the opening speech for the Commonwealth summit.
Women as Agents of Change - Animated Film