How is Ethel unkind to Marianne in regard to Marianne's grandmother's death in the novel, We Were the Mulvaneys?

It is Ethel who calls and informs Marianne that her grandmother has died. Ethel also, very unkindly, tells Marianne that she is not welcome at the funeral as per her own mother's instructions. The only reason Ethel calls her, she says, is because it is the morally correct thing to do.