I wish my mother believed in me this much
Context: After the fall of Imperial Russia, Maria Feodorovna the Empress Dowager and mother to the last Tsar Nicholas II never acknowledged her sons death nor the death of Nicholas' wife and children. She maintained until her death, that her son was still alive and that the Bolsheviks were lying.
There are accounts that Maria had a letter addressed (dated 5 months after his death) to him in her effects when she died and she always mentioned him in the present tense. There is also an account that she kept a large, framed photograph of Tsar Nicholas II by her bedside, along with icons and images of her husband, Alexander III. (Source: Little mother of Russia : a biography of the empress)
Her final diaries contained numerous entries addressed to her dead sons (both Nicholas and Michael), written in a conversational tone as if they were still alive. (Source: The Last Grand Duchess: Her Imperial Highness Grand Duchess Olga Alexandrovna)
She had two living daughters who lived into their 70s and 80s.
Edit: A word