Step 1: Understanding the theme of the poem.
"Aunt Jennifer's Tigers" by Adrienne Rich deals with themes of oppression and freedom. The poet describes Aunt Jennifer's creation of vibrant tigers in her embroidery, which represent the power and courage that she lacks in her real life.
Step 2: Identifying the core message.
The central idea of the poem is about the contrast between Aunt Jennifer's vibrant, fearless creations and her own repressed, fearful existence. The tigers symbolize strength and freedom, while Aunt Jennifer's life is marked by the constraints imposed by society and her own circumstances.
Step 3: Conclusion.
Thus, the central idea of "Aunt Jennifer's Tigers" is the contrast between the artist's idealized creations and the realities of her life, reflecting themes of female oppression and the desire for freedom.
Final Answer: \[ \boxed{\text{The central idea of "Aunt Jennifer's Tigers" is the contrast between Aunt Jennifer's powerful, free creations and her own oppressed life, symbolizing the themes of female oppression and the desire for freedom.}} \]