She is the girl lately actor Cyril Cusack & the late Maureen Cusack, and is the sister of actresses Sorcha Cusack, Niamh Cusack and Catherine Cusack.

Her 1st acting roles were at a Abbey Theatre in Dublin, then around 1975 she moved to London and joined the Royal Shakespeare Company. One of her better known stage roles was My Lady of Sligo inside 1998, in which she played a chief role of Mai O'Hara around performances inside Ireland, in Broadway and at the National Theatre.

She was awarded a 1998 Evening Standard Award for Better Actress & a 1998 Critics Drama Award for Best Actress.

She married British actor Jeremy Irons in 1978, & has deuce sons, Sam and Max.

Quotes
"Acting is the shy person's revenge on the world."