Niamh was first diagnosed with a rare form of cancer at just 3 years old, after receiving the all clear after a spell of chemotherapy she was re-diagnosed at the age of 15.
On the 5th and 6th of December there will be a 24 Hour TV Broadcast in aid of the Histiocytosis Research Trust, an organisation working to cure her condition.
This is her story.
Filmed, Directed and Edited by: Mark Kelly.
Audio by: Deirdre McGrath.