The Cast of Mrs Brown's Boys is almost entirely made up of Brendan O'Carroll's family members. Jennifer Gibney (Cathy) is Brendan's wife. Eilish O'Carroll (Winnie) is Brendan's sister. Fiona O'Carroll (Maria) is Brendan's daughter. Danny O'Carroll (Buster) is Brendan's son. Amanda Woods (Betty) is Brendan's daughter-in-law, married to Danny O'Carroll. And Martin Delany (Trevor) is Brendan's son-in-law, married to Fiona O'Carroll.