She will tell of the break-up of her first marriage, her fights with depression and later cancer and her life now with singer and husband Daniel.
It’s All in the Head: My Story, charts her life story.
The book will be released on October 9 by UK publishers Simon & Schuster just two weeks after her sister in law Margo O’Donnell launches her biography.
Majella covers her decision to have her head shaved for cancer charities on the Late Late Show.
“It was a public declaration from a private woman, a statement of enormous courage in her fight against breast cancer,” according to her publishers.
Majella’s publishers promise readers a compelling story about “a woman who has learned about life the hard way, but who, with the love and support of her family, husband Daniel, and the public by her side has come through with a force of character and a deep-seated determination that will inspire us all”.
Yesterday Daniel and Majella jointly undertook the Ice Bucket Challenge at The Irish Fiddler pub in Tenerife, making donations to both motor neurone and cancer services in Ireland. Daniel nominated Irish singer Dominic Kirwan, while Majella nominated Noeleen Murphy of the Irish Fiddler pub.