Final answer:
The book 'The Giver' does not provide a specific rule for all females under the age of nine, but it illustrates a society with stringent controls set by the Elders.
Step-by-step explanation:
The rule for all females under the age of nine in The Giver is not explicitly detailed within the text of the book. In Lois Lowry's dystopian novel, society is governed by strict rules regarding behavior and societal roles, but specific regulations for females under nine are not directly described. The narrative focuses on a society where individualism is suppressed, and all aspects of a citizen's life, including children, are controlled by the community's Elders. While the book touches on various rules regarding the developmental stages of children, such as hair ribbons for young girls to distinguish their growing maturity, it does not mention a unique rule that applies specifically to all females under nine.