How did Mary tie together the news of the jellyfish attack with the news of Grandma Moore's death?

While on the beach, watching Lecia be attacked by the jellyfish, Mary was overcome with a fear that she had entered into an inadvertent agreement with God. She had spent so long praying for her grandmother to die that she thought she had made a deal with God and now he was collecting payment by taking Lecia too. While Lecia was recovering, Mary prayed for her full return to health and was overwhelmed with joy when Lecia made a full recovery.