Mr. Knowitall is correct, you need to look at the contract.
But, you also need to look at the social security payments and the way that they are made. SS Payments to you for your daughter are not income to you and are not your money. (Income Tax-wise you should be filing a return for your daughter showing that income, or the IRS may try to collect taxes from you as though it were your own). YOUR SS payments should be made to you. Your daughters should be made to you FOR HER - it should show that way on every check from SS.
This is easily mixed up and can work against you. You need to keep the paperwork straight; noone else will do it for you. The net effect is that your daughter's payments should NOT count against your disability.
You've got another serious problem going on if you are paying your ex child support while the child is living with you. That is not right; I'd suggest that you have your attorney revisit that.

