Federal prosecutors say 60-year-old Marlou Mendoza of Long Beach, California, and her son were indicted last month. She was arrested last week at Los Angeles International Airport after returning from her native Philippines.
She pleaded not guilty last week and is free while awaiting trial.
Her son, 30-year-old Mark Mendoza, is a fugitive and is believed to be in the Philippines.
Prosecutors say he ran a business called Last Resort Armaments.
Authorities say that in 2011 the pair tried to smuggle hundreds of thousands of ammunition rounds and parts for assault rifles to the Philippines, labelling the shipments as household goods.
They were intercepted by U.S. and Philippine authorities.