non dependent deductions - is child tax credits counted as income?

I have a client who receives income based ESA.  She has non-dependants living with her, namely her adult son (over 25), his wife and their 4 children.  The son works 16 hours per week and they receive, in addition to his earnings, working tax credits, child tax credits and child benefit.

For the purposes of calculating the income of non-dependents, would child benefit and child tax credits count or would they be ignored, since they are benefits for the children, for whom no deduction would be made?

I assume that working tax credits income would count, but please correct me if you think I’m wrong on this.

Thank you

pretty much all income of a non dependant is counted except for DLA / AA / independant living fund