In most cases it's impossible for a custodial parent to get by without working, so child care is often needed on a day-to-day basis. Child support law usually taps the non-custodial parent to pay for child care, so expect this to be a part of any child support deal.
Under child support law, annuities such as worker's compensation and personal injury payments are considered to be personal income for purposes of child support, even if they are otherwise untaxed. This is well-established law, and would be difficult fight in court.