Foua is the mother of the main subject of the book, Lia Lee. She fights to heal her daughter using traditional Hmong remedies, and resists modern Western medicine. Unfortunately, she ends up losing her daughter to a coma. Lia Lee ended up passing away years after the book was published. This, obviously, is the most significant loss Foua sustains in the book. The other significant loss is the loss (to her and her family) of her home country of Laos.
Foua does keep something very important throughout the events of the book. She is able to keep her dignity despite great hardship and adversity. Not only does she lose her daughter, she nearly loses her culture. Her strength in the face of adversity allows her to hold onto this, at least.