Ama is Lakshmi's mom, and it's from her that Lakshmi takes her cues for strength and resilience. She works hard, treats her husband well, and tries to scrape together a life for herself. Lakshmi recognizes her mother's sacrifice and the beauty in it:
But my ama, with her crow-black hair braided with bits of red rag and beads, her cinnamon skin, and her ears hung with the joyful noise of tinkling gold, is, to me, more lovely.
And her slender back, which bears our troubles—and our hopes—is more beautiful still. (4.SomethingBeautiful.6-7)
What Ama wants more than anything else in the world is a better life for her family. This is the reason she sells her earrings… and loses her pride.
I watch for Ama on the path below, and wonder what will be lost next.
Later, when I see her climbing he hill to our hut, I know.
It is the joyful noise of her earrings. And the proud set of her head. (27.ThePriceofaLoan.4-6)
Because of the actions of her husband and because of the destruction of the monsoon, Ama must give up her earrings—which were supposed to be Lakshmi's dowry—so that she can feed her family. And even when she and Lakshmi and the baby make hearty, rich food for the first time in weeks, she sacrifices her own portion for her children. It's hard to imagine anyone more selfless and willing to sacrifice for the love of her children.
But Ama's main weakness is what changes the course of Lakshmi's life forever. Ama believes that "a man who gambles away what little we have on a fancy hat and a new coat […] is better than no man at all" (29.Stranger.8)—and this blind acceptance of the social gender roles that exist on the mountaintop removes any agency that Ama might have for challenging her husband's edict that Lakshmi must leave the village to earn money.
Ama's presence in the novel is brief but significant. We see her internal strength and her mischievousness when she steals her husband's cigarette—but we also see her acquiesce to her husband's needs and desires, even when confronting his behavior would arguably be better for the good of the family. Like Lakshmi, Ama's contradicting actions—her assertions that Lakshmi must attend school contrasted with her giving in immediately to her husband's demand that Lakshmi go work in the city—imply that there's far more depth to this woman than we see in the novel.