Who is Arjumand (Jahanara's daughter) from Beneath a Marble Sky: A Novel of the Taj Mahal and what is their importance?

Jahanara and Isa have a daughter they name Arjumand. Jahanara convinces the unaware Khondamir that the girl is his child, but reveals to her daughter the truth when Aurangzeb comes to take the city. Arjumand flees with her real father, Isa, and Jahanara does not see her again until she is almost a woman.