She was the fourth child of eight born to Te Marino (a freezing works worker of the Ngāi Tahu tribe) and Bernice Reuben (a Pākehā homemaker).
[3] She left high school after four years to work as a hospital laboratory assistant, then seven years later applied for support from the Ngāi Tahu Māori Trust Board to attend medical school.
On graduating, she moved to Wellington and worked at Porirua Hospital in general medicine before deciding to specialise in psychiatry.
In 1996 she was appointed to the board of Ngāi Tahu Development Corporation, and the following year she became chair.
[5] In 2004, Ryan received the Dr Maarire Goodall Award acknowledging her contributions to Māori health.