IB - withdrawal of adult dependent addition

My client is in receipt of LT IB 160.44 (91.40 basic + 15.94 additional pension + 53.10 dependent addition)
Her Housing Costs are no longer payable due to the decrease in interest rate; she has 48p too much income.
Her husband does not work and has been caring for her for 19years - I am trying to maximise their income and ofcourse, their biggest concern is the mortgage.

Would it be possible to request a withdrawal of the dependent addition of £53.10 so that they are entitled to help with Housing Costs?

Your assistance is much appreciated.

If you give up income in order to claim or increase benefit, it can be regarded as a notional income and treated as if it is still being paid. Also, if your client gives up the adult dependent addition, it won’t be possible to reclaim it in the future.
I would be looking at her entitlement to DLA, if she can get middle or higher rate for care, her husband can claim carers allowance instead of her claiming the adult dependent addition on Incapacity, and the carer premium will be included in her IS allowance which will bring them back into IS and housing costs entitlement