161D.—The increase payable under section 161B(1) in respect of a qualified child who normally resides with the beneficiary and the spouse F971[, civil partner or cohabitant] of the beneficiary shall be payable at the rate of one-half of the appropriate amount in any case where the spouse F971[, civil partner or cohabitant] of the beneficiary is entitled to any benefit, assistance, allowance (other than supplementary welfare allowance) or any other pension under this Act.]