(1) The weekly rate of invalidity pension shall be increased by the amount set out in column (3) of Part I of the second Schedule for any period during which the beneficiary has an adult dependant, subject to the restriction that a beneficiary shall not be entitled for the same period to an increase of pension under this subsection in respect of more than one person.
(2) The weekly rate of invalidity pension shall be increased by the appropriate amount set out in column (4) or (5) of Part I of the second Schedule in respect of each qualified child who normally resides with the beneficiary.
(3) Any increase of invalidity pension payable pursuant to subsection (2) in respect of a qualified child who normally resides with a beneficiary and with the spouse of a beneficiary shall be payable at the rate of one-half of the appropriate amount in any case where the spouse of the beneficiary is not an adult dependant, and subsection (2) shall be construed and have effect accordingly.
(4) Th