Who is Princess Jahanara from Beneath a Marble Sky: A Novel of the Taj Mahal and what is their importance?

Jahanara is the main character of the novel. It is her story and she tells it from her point of view in first person. She is the eldest daughter of the seventeenth century Mughal Emperor, Shah Jahan, and his beloved wife, Arjumand. Her brother, Dara, heir to the throne, is older by one year.