Mariam is the illegitimate daughter of wealthy business owner Jalil and his former housekeeper, Nana. The first fifteen years of her life are lived with Nana in a kolba, a shack her father built as penance for his adultery. Mariam grows up respectful to Nana, quietly heeding her diatribes and adoring of Jalil, whose stories help her imagine a world beyond the kolba. Her sense of entitlement leads her to visit the house Jalil lives in with his legitimate family. When he rejects her, she learns that being a harami, a bastard, is a sentence towards a lifetime of exclusion.

Mariam’s subsequent loss in confidence and sense of low status is reflective of the treatment she accepts from her misogynist husband Rasheed. She feels that the burqa he makes her wear is a buffer “from the scrutinizing eyes of strangers” (72).

Mariam is on the plainer side, with “archless, unshapely eyebrows […] eyes mirthless green and set so closely together that one might mistake her for being cross-eyed” and a long chin (53). As a result of Rasheed’s beatings, she also loses teeth and ages prematurely; nevertheless, by the time she has come to know the unconditional love she experiences with Laila and Aziza, she possesses the radiance of the “thousand splendid suns” that give the book its title (381).