Shannon was born in Dublin, Ireland and relocated to London with her family as a young child. She attended drama classes with Anna Scher until the age of 14 when she was paralyzed in diving accident whilst on holiday. She subsequently went on to become the UK's first professional model with a disability and campaigned for better representation of people with disabilities in the media & advertising. Shannon studied Law at university and qualified as a solicitor whilst continuing to pursue her career as an actress. She now divides her time between London and Los Angeles. In 2019 Shannon was named in the Power 100 as one of the most influential disabled people in the UK.