Alison was born to Alicia and a factory worker.
Her father died months before her birth in a factory accident.
Alicia committed suicide hours after giving birth to Alison by jumping out of her second-story hospital room window. It is possible that she was trying to abandon her daughter so Morpheus didn't connect to her daughter's mind though hers, as he did with Alison and her daughter, Alyssa Gardner. When Alyssa discovered the wings that came with her own Netherling heritage, she pondered that perhaps Alicia didn't get high enough to allow her wings time to unfold.
Alison was left to be raised be a long line of foster parents. At age 13, she came into her Netherling inheritance and began plotting with Morpheus. They developed a workaround for the Queen requirements and Morpheus carried Alison down the Rabbit Hole to Wonderland at age 16.
While attempting to steal Chessie's smile, Alison took a wrong turn and found Sister Two's 'mortal dreamer', a man she later named Thomas Gardner. She bargained with Sister One, trading the boy's life for an army to help Sister One track down delinquent souls when Alison came back to claim the crown. Queen Ivory erased all 19 years of his life from his memory and Alison took him through the portal to her bedroom and then to the hospital.
Around the end of Unhinged, Alison helps Morpheus, Jeb, and Alyssa to defeat Queen Red while she tries to crash the prom.