Paying tribute to her bravery and honouring her courage, Avery's mum and dad started an online Twitter campaign using the hashtag 'AveryStrong'.
Upon learning of the little girl's heartbreaking struggle, Hollywood star and mum-of-two, Kristen Bell, slipped into character and left Avery a message as much-loved Frozen character, Anna.
Crowning the little girl an 'honorary princess' on the guidance of her sister Elsa, Anna left Avery in no doubt that she was a much cherished and 'incredibly brave' little girl.
Having amassed over 60,000 hits since its upload to YouTube earlier today, this heartwrenching video has clearly touched people all over the world.
Take a look at the moment Princess Avery heard from her friend, Anna.
