It would be advisable to check with the court clerk in your state court to determine whether or not your notarized agreement on child support would be acceptable because the rules vary from state to state.  Some states use a mathematical formula for calculating the required minimum amount of child support which is based on income and other factors.  Some states will allow the spouses to agree to a level of child support which is below the minimum.  Again this varies from state to state, and it would be advisable to check with your court clerk to determine whether or not your notarized agreement pertaining to child support is valid.