Annamaria Gana, 41, is charged with murder and attempted murder.
Prosecutors said she fired into the ceiling of her Tustin home. When her 72-year-old husband and 16-year-old son ran in to see what happened, she opened fire on them.
Her husband, who was hit in the chest, died. Her son, who was hit in the arm, ran out and dialed 911.
Her 9-year-old son managed to get the gun away from his mom and get out of the house.