In paragraph 2, "that she had heard aright" refers to Louisa's belief that

Joe has an intimate relationship with Lily

Joe has spoken rudely to Lily

Joe has confessed his love for Louisa

she has perhaps spoken too candidly

she has certainly misconstrued Joe's remarks

In paragraph 2 that she had heard aright refers to Louisas belief that Joe has an intimate relationship with Lily Joe has spoken rudely to Lily Joe has confesse class=