Pilkington advance

I have a court order (following a 1975 Act claim) which states that funds should be held by A “to place into an interest bearing account to be made available to B when he is 18 subject to earlier payments made at the discretion of A”.

B is currently 17 and not great with money, and his mother (A) wants to postpone his entitlemet. Is there any reason why a Pilkington type advance cannot be made in this matter? I am concerned A would be overriding the court order, and do not want her to be in contempt.