(1) Where a person qualifies for an incapacity supplement under section 77, disablement pension shall be increased for the period during which incapacity supplement is payable - 

(a) by the amount set out in column (3) of Part 4 of Schedule 2 for any period during which the beneficiary has a qualified adult, subject to the restriction that a beneficiary shall not be entitled for the same period to an increase of disablement pension under this paragraph in respect of more than one person,

(b) in column (4) of Part 4 of Schedule 2 in respect of each qualified child who has not attained the age of 12 years who normally resides with the beneficiary,

(bb) in column (5) of Part 4 of Schedule 2 in respect of each qualified child who has attained the age of 12 years who normally resides with the beneficiary,