To clarify Kloss, the family benefit (can be your kids, stepkids, or divorced spouse caring for the kids) can be UP to 50% of the total ssdi amount.

Your total income (including family benefit) can't be more than 80% of your total pre disability income. In my case, I also still get partial worker's comp, so they just lowered my ssdi so they could give my kids $60/month each (my ssdi was 1980, so I thought my 2 boys would get $490 each)