Sallie Gardiner, Meg March's friend of similar age, hails from a significantly wealthier and higher-class family. This disparity prompts Meg to frequently compare her own modest circumstances with Sallie's life of luxury, sometimes fostering envy towards Sallie's advantages and possessions. Sallie's lifestyle represents a constant temptation for Meg, particularly during Moffat family gatherings where displays of wealth challenge Meg's values and occasionally lead her to compromise her identity, such as allowing herself to be dressed extravagantly.

Sallie marries Ned Moffat, securing her continued affluence and leisure. Despite their differing financial situations and life paths, Sallie and Meg maintain their friendship. Sallie visits Meg and John Brooke in their simpler home, demonstrating genuine appreciation for the warmth, peace, and authentic happiness characterizing the Marches' humble lifestyle. Her admiration for their domestic contentment validates the significance of Meg's choices and highlights the value of a life built on love over material excess.

Within the narrative, Sallie tests Meg's character development and underscores the contrast between wealth-driven and values-driven lives. Her obliviousness to Meg's practical struggles emphasizes the gap between their worlds. However, her consistent friendship and sincere happiness for Meg, despite divergent circumstances, indicate a fundamental kindness. She remains a supportive figure, symbolizing luxury's allure while ultimately recognizing and respecting the beauty in Meg's chosen path of simplicity.