Sentence:  Here, in what she had begun to think of as the <WSD>Indian summer</WSD> of her life, she was claiming a future that held infinite and delicious possibilities; and she would spend the coming years with someone who would bring all the seasons alive. 
Meaning of the word marked with <WSD> tags:  The late autumn of life; a late flowering of activity before old age. (from early 19th c.)