Who is Eleanor Stier from A Beautiful Mind: A Biography of John Forbes Nash, Jr., Winner of the Nobel Prize in Economics, 1994 and what is their importance?

Eleanor Stier was a Boston nurse from the Jamaica Plain section of Boston. She had an affair with Nash and bore his son, John David Stier, on June 19, 1953. She and Nash did not marry and he did not support her after the baby's birth. Eleanor had to place the child in foster care. Their affair lasted for four years. She remained in touch with Nash because of their son.