4. For the purposes of this Act:(a) persons are connected by blood relationship if one is the descendant of the other, or is his or her brother or sister;
(b) persons are connected by marriage, a civil union or a de facto union if one is connected with the other or with a person connected with the other by blood relationship or by adoption; and
(c) persons are connected by adoption if one has been adopted, legally or de facto, and would be connected with the other by blood relationship or by marriage, a civil union or a de facto union if his or her filiation by adoption were filiation by blood.