Unfortunately there is no provision for childminding costs to be taken into account for JB or JA. I couldn't say for sure if you will qualify for JA with your husband's wage, it will depend on how many kids you have, and how much income you're getting from your own job, but if you do qualify, then you're likely to get a very much reduced payment.
Have you applied for Family Income Support (FIS)? At least with FIS they don't take tax into account when calculating your gross earnings, which they do for JA. Check the welfare webpage or citizens information page for details to see if you qualify, sorry i can't post a link as i'm only new here, perhaps someone else can do that for you.