TMZ has obtained documents from the Britney Spears/Kevin Federline hearing last Monday that reveal Spears's salary to be an average of $737, 868 a month. Federline's lawyer claims in a declaration filed last Monday that Spears "is clearly the 'monied party' in this case." The lawyer is asking Spears to front $50,000 for expenses in connection with the custody hearing, claiming his bill will be in excess of $40,000. The documents reveal that Federline is receiving $20,000 a month for spousal support but the payments end November 15. The papers also show that the LA County Department of Children and Family Services is investigating Spears for allegedly neglecting her kids. The allegations? Poor dental hygiene as well as poor eating and sleeping habits.