The narrator is Chinese and is living with her daughter in America. Her daughter has married an Irish man, and they have a daughter together. The tension between the married couple and the narrator is likely as generational as cultural, but living together proves to be too much in the end.
The grandmother sees her granddaughter's "wild" tendencies as being particularly Irish, feeling that her "nice" Chinese genes are being "swallowed up" by her wild Irish genes. Sophie insists on running around naked, much to the grandmother's horror. She blames this on a lenient babysitter named Amy who taught Sophie that it was okay to do so. The narrator says that Amy was too "creative," which is not something Chinese people ever value, according to her. She reflects that Americans sit around talking all day about the importance of creativity, whereas Chinese are more worried about life's difficulties.
The narrator also mentions that she used to believe that the Irish and the Chinese had a great deal in common, both hardworking people who had spent long years laying railroad lines. After getting to know her son-in-law, she comments that she now knows "why the Chinese beat the Irish." Her son-in-law suffers from depression and cannot work, and the grandmother believes he is a product of his culture. She doesn't accept his excuse that he is unable to care for his daughter just because he is a man, and she maintains that if he lived in China, he'd be plenty happy with all he's been afforded.
In the end, "wild" Sophie pulls a stunt at the playground and hides in a hole so deep that her grandmother cannot get her out. Because she's been poking Sophie with a stick to try to force her to come out, Sophie is covered in bruises, and Sophie's father, who is typically a hands-off parent, is furious.
The narrator comes from a hardworking culture, and she has those same expectations for the man who marries her daughter. The American/Irish philosophies of raising children and the Chinese philosophies of raising children clash in the embodiment of Sophie, whom the narrator loses contact with after the park incident. The story shows that the conflict resulting from cultural differences can have devastating effects on personal relationships if left unchecked.