Child Tax Credits and Employment and Support Allowance

Hi,

My wife is receiving Employment and Support Allowance (and has beeneh last 3 or so years). We now have a child and following her appeal she has had Employment and Support Allowance re-instated and backpaid. My question is - do we declare Employment and Support Allowance as her income? (I have searched and apparently in some cases you do and in others you dont). Can anyone advice what it depends on before i call tax credits support to update our records?

Thank you