if you get smi help with your mortgage is this taken off benifits you recieve regards

hi i shall keep this as short as possible my wife is now about to be unemployed after being a student and im self employed we have 2 children aged 10 and 7 i have been told that when she claims jsa(meand tested as she has not paid any national insurance) that they look at my income also which is £3000 last year(going to give it up soon) the question is iv been told they say as a couple with 2 kids you must get £350 a week then they take off my salary to get a figure have i got this right please any advise greatly appreciated