What does Mama Elena's ghost represent in "Like Water for Chocolate"?
When Mama Elena's ghost appears to Tita, it tries to reassert the control that this mother had in life over her daughter. As the youngest daughter, it was Tita's "job" to remain unmarried and care for her mother until she died. Tita did her duty, but was torn between her passion for Pedro and her family responsibilities.
When Tita gives in to her passion for Pedro, Mama Elena's ghost appears to make her feel guilty and remind her of the traditional role she is neglecting. The ghost represents authority, control, and the imprisoning nature of frustrated love.