105Members of a person's family
(1)A person is a member of another's family if—
(a)he is the spouse of that person, or he and that person live together as husband and wife, or
(b)he is that person's parent, grandparent, child, grandchild, brother, sister, uncle, aunt, nephew or niece.
(2)For the purposes of subsection (1)(b)—
(a)a relationship by marriage shall be treated as a relationship by blood,
(b)a relationship of the half-blood shall be treated as a relationship of the whole blood,
(c)the stepchild of a person shall be treated as his child, and
(d)an illegitimate child shall be treated as the legitimate child of his mother and reputed father.