disability living allowance used as income in debt recovery

not sure if I’m posting this question in the right section. Strictly speaking it’s a debt issue rather than a benefits issue but thought I’d try anyway. i have a client whose wife has a benefit overpayment. She is in receipt of IB and DLA after a stroke. Recovery of the benefit overpayment was set at approx £20.00 per fortnight but following a review it has increased to £66.00 per fortnight. Her DLA is being counted as income (it was when the lower level of repyment was set as well). generally, since DLA is awarded for care and mobility, it is not counted as income when it comes to repyment of debts.

Does anyone know whethet it is legitimate for the DWP to count DLA as income?

Section 73(14) of the Contributions and Benefits Act prevents the mobility component being included in a means test but there is nothing, as far as I’m aware, that stops the care component from being included.