Why does Annemarie say she is equal with her mom on page 79 of Number The Stars Chapter 9

Annemarie knew she was equal to her mother at this point in the story on page 79. Annemarie had figured out that her mother and uncle hadn’t been telling her the truth about who was in the coffin. Annemarie never heard of the aunt that supposedly died. She found it strange that there was no phone call about the death of her aunt.
Annemarie understood at this point that the story about this aunt was made up to protect Ellen. When Ellen told Annemarie that she was sorry for the death of her aunt, Annemarie chose to say nothing. Annemarie knew she was now protecting Ellen, by not sharing information with her, just like Annemarie’s mother had been protecting her. When Annemarie’s mother told her that friends of the deceased aunt had arrived, Annemarie and her mother exchanged glances. Her mother knew that Annemarie understood that this wasn’t true and that a greater goal was involved at this time. It was at this point that Annemarie and her mother were equals because each person was trying to protect somebody, even if it meant not being totally honest.
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