Nebraska authorities believe a mother accused of pimping out her 14-year-old daughter also charged men to have sex with her 7-year-old daughter.

The Nebraska State Patrol says the 35-year-old mother allowed at least seven men to have sex with her 14-year-old at least 20 times. Investigators say at least three men had sex with the 7-year-old.

The Lincoln Journal Star reports three men have been arrested and charged with sexual assault of a child. Investigators are working to identify and locate the others.

The mother is charged with child pornography and with conspiracy to commit sexual assault of a child, and she remains jailed in lieu of $250,000 bond. The Associated Press is not using her name, to protect the identity of the girl.