Prosecutors say the woman knew about the abuse but didn't stop it.
Her husband was sentenced last June to life in prison after being convicted of second-degree murder and abandonment of a corpse.
Three of the four children the man had with his daughter died, including one whose body was found in a shallow grave in eastern Oklahoma where the family apparently lived for a short time.
The murder charge stemmed from the death of a child who died after falling ill.
The Associated Press is not identifying the parents to protect the victims' identities.
