(1)The relation of one person (A) to another (B) is within this section if—
(a)it is within any of subsections (2) to (4), or
(b)it would be within one of those subsections but for section 67 of the Adoption and Children Act 2002 (c. 38) (status conferred by adoption).
(2)The relation of A to B is within this subsection if—
(a)one of them is the other’s parent, grandparent, brother, sister, half-brother, half-sister, aunt or uncle, or
(b)A is or has been B’s foster parent.
(3)The relation of A to B is within this subsection if A and B live or have lived in the same household, or A is or has been regularly involved in caring for, training, supervising or being in sole charge of B, and—
(a)one of them is or has been the other’s step-parent,
(b)A and B are cousins,
(c)one of them is or has been the other’s stepbrother or stepsister, or
(d)the parent or present or former foster parent of one of them is or has been the other’s foster parent.
(4)The relation of A to B is within this subsection if—
(a)A and B live in the same household, and
(b)A is regularly involved in caring for, training, supervising or being in sole charge of B.
(5)For the purposes of this section—
(a)“aunt” means the sister or half-sister of a person’s parent, and “uncle” has a corresponding meaning;
(b)“cousin” means the child of an aunt or uncle;
(c)a person is a child’s foster parent if—
(i)he is a person with whom the child has been placed under section 23(2)(a) or 59(1)(a) of the Children Act 1989 (c. 41) (fostering for local authority or voluntary organisation), or
(ii)he fosters the child privately, within the meaning given by section 66(1)(b) of that Act;
(d)a person is another’s partner (whether they are of different sexes or the same sex) if they live together as partners in an enduring family relationship;
(e)“step-parent” includes a parent’s partner and “stepbrother” and “stepsister” include the child of a parent’s partner.