The reader is first introduced to the character of Grandma through the lens of Oskar and his relationship with her. The two of them are very close, and when he is young they communicate a lot through walkie-talkie at all hours of the day and night. This detail tells the reader that Grandma is a loving and compassionate woman who cares about her family.

Later, through the letters that Grandma writes to Oskar, the reader learns more details about her life and how she ended up writing to Oskar from an airport. Grandma raised Oskar’s father by herself because her husband (Grandpa) left when she got pregnant. Grandpa left because he was unable to cope with change. He married Grandma after coping with trauma from war and the loss of his love, Grandma’s sister. Grandma and Grandpa had agreed on various rules when they were married, including never to have children. The rules demonstrate how they both are people who strive to have a lot of control over their lives and emotions.

Grandma’s perseverance through this tumultuous relationship and her dedication to raising her son by herself also shows the reader that she is strong and independent.

Foer develops Grandma as a character who cares a great deal about her family in a way that is fiercely protective. For example, consider how the renter who moves in with her is actually Grandpa. Similar to the rules that the couple set decades ago, Grandma tells Grandpa that Oskar can never find out who he is. Grandma cares about Grandpa and cautiously lets him back into her life to grieve alongside her, but she does not want Oskar to know because she doesn't want him to be emotionally hurt the way she once was by Grandpa. This scenario underscores the ways in which Grandma balances her relationships and her actions to protect the ones she loves.