What are Erickson's psycho-social stages of development for Beth, the mother, in the movie Ordinary People?

Beth, the mother character (played by Mary Tyler Moore) in the movie Ordinary People, is in Erikson's stage of intimacy versus isolation. In this stage, which characterizes the psychological and social tasks that people roughly from ages 18-40 face, people engage with the task of forming relationships in which they feel connected and loving towards others. If they struggle with forming committed, close, and loving relationships, they feel a sense of aloneness and isolation.
Beth cannot really form close bonds with her family, particularly with her son Conrad, following the death of her older son. She cares more for appearances and for restoring the outward semblance of functionality in her family than she cares about connecting with her son and the pain and guilt he feels over the death of his older brother. She seems to relate to people only in a symbolic sense—for example, she believes because they are a family, they should act a certain way—and she does not achieve a sense of intimacy with her husband or son. Instead, she decides to leave the family in the end because she cannot achieve true connection with them. At the end of the movie, she disengages from intimacy and chooses isolation instead.