The change of rules was implemented to allow Prince William and Kate, Duchess of Cambridge’s first child to take precedence in the line of succession, regardless of their gender.
The terms of the act state: “In determining the succession to the Crown, the gender of a person born after October 28, 2011 does not give that person, or that person’s descendants, precedence over any other person (whenever born).”
But the changes did not apply to any royals born before the act was passed, meaning Lady Louise Windsor remains below her brother in the line of succession.
The Succession to the Crown Act only applies to the line of succession, meaning hereditary titles remain only inheritable by men.