The woman pretended to relatives that charges against former Grangemouth man James Smith had been dropped.
However, Smith was on bail awaiting trial and eventually he was jailed for four years and eight months for child abuse and breaching bail conditions.
His 25-year-old girlfriend, who cannot be named, appeared at Hamilton Sheriff Court last week. She admitted exposing her daughter to the risk of sexual harm by allowing Smith (32) to return to her home in Motherwell last year.
Smith, formerly of Cultenhove Crescent, Grangemouth, was convicted earlier this year of abusing the girl and the four-year-old son of a woman he was seeing in Falkirk in 2012.
After the offence in Falkirk came to light, Smith was given bail and ordered to stay away from children. However, he met up with the woman in Motherwell in 2014, moved into her home and abused her daughter.
Again he was given bail to await trial and during this period the woman let him back to live with her, the abuse victim and another young child.
Lauren McRobert, prosecuting, told the court the little Motherwell girl and her young brother were put on a child protection register after Smith was charged with abusing her.
Later they were taken off it, but social workers continued to have regular contact with the family, checking Smith was staying away.
The woman assured them repeatedly he was not living with her and allowed her sister’s children to stay overnight at her house.
Her sister was then told by one of her children that Smith had been in the house. When the woman asked her sister about this she was told the charges against Smith had been thrown out.
It was only when she saw press coverage of the trial that she realised he had been convicted of abuse.
The horrified woman asked her children if Smith had done anything to them when they stayed overnight, but they said no. She confronted her sister who apologised for deceiving her and other family members. She said she loved Smith.
The mother of the abuse victim told police she had allowed him unsupervised contact with her daughter and son. She had ordered her daughter not to tell anyone Smith was living with them.
The woman is on bail and will be sentenced by Sheriff David Bicket next month.