Esa and other income

Hi I care for my severley disabled wife who has multiple sclerosis she has been unable to work since 1997 and since 1998 has been claiming incapacity benefit, and a health insurance taken out by her employer which pays a percentage of her salary minus ic while she remains an employee albeit in name only this is paid in its gross form monthly and we are responsible for paying the tax through the self assessment process. She also receives a small pension from a previous employer where tax is paid at source. Under incapacity benefit neither of these incomes were taken into account. My wife migrated to esa in November last year and we asked the lady who phoned if other income would be affected and she said no as my wife was put in the cb support group.
My question is this I know dwp are aware of the pension from the paye code but we never had to mention the insurance as it was never looked at by ic and we were asked no financial questions on the esa questionaire as we self assess to pay the tax on this I doubt they know about it but both incomes were disregarded by ic and as my wife was in reciept of ic prior to April 2001 and is in the highest rate of care for dla should as I understand it be disregarded for esa can anybody confirm I'm right on this . Thanks