"No treatment, no cure, only palliative care. I'd waited too long to look after myself and my body broke. It's time to leave the work to others now."
She adds: "I'm now focused on the moments of magic that are appearing in front of me: The laughter of my grandchildren; a smile of a friend attempting to walk this journey with me and the pure beauty and strength of my adult children as they battle their anger, grief and sadness at what is happening to their beloved mother."
Lashlie's work on raising teenage boys as well as on social justice issues saw her in demand for speaking in New Zealand, Australia, South Africa and the United States.
Her statement today said: "Celia and her family hope that much of this work will continue through public support to honour her extensive contribution to social justice and her dream to improve the lives of at-risk families in order to reduce crime and poverty in this country."
She is best known for her work with the "Good Man" project that focused on research from discussions with pupils in 25 boys' schools throughout the country. It formed the basis of her book, He'll Be Ok, Growing Gorgeous Boys into Good Men.
She has also written two other books; The Journey to Prison: Who goes and why and The Power of Mothers: Releasing Our Children.
Her advice to mothers of boys became well-known.
If adolescent boys could tell their mothers one thing, what would it be, she famously asked? Chill out and stop asking so many questions, was her answer.
Lashlie worked for 15 years within the Prison Service from 1985. She was the first woman to work as a prison officer in a male prison in New Zealand.
Her website, perhaps summed up her later work with its motto: "Every child is born pure and filled with their own particular brand of magic."
She is the mother of two adult children and "Nana'' to five grandchildren.
Her family has asked for privacy as Celia has chosen to stay in her Wellington home surrounded by her family.
Lashlie was a New Zealand Herald New Zealander of the Year in 2005.
- nzherald.co.nz