A Mills woman has entered a plea in court in a case where she's accused of engaging in sex within the family, endangering children and then lying to law enforcement.

Thirty-three year old Robin Keene has pleaded not guilty to one charge of incest, two counts of child endangering, and one count of false reporting.

According to the Natrona County Sheriff's Office, the investigation began in September, when deputies received a report from a counselor, about a girl who had been sexually assaulted by her grandfather, later identified as 53-year old Glenn Towner.

An interview with the other granddaughter revealed that she had been touched inappropriately.

These repeated contacts started as early as September 2013.

One girl has been placed in protective custody, the other lives out of state.

The granddaughters told investigators that they told Keene in September and October of 2013, and also in August 2014, about the sexual contacts with Glenn Towner.

Keene then confronted Towner about the contact and also told law enforcement that Towner also touched her and that she was a victim of sexual abuse, however investigators later found text messages sent from Keene to Towner and when questioned, Keene admitted to having a consensual sexual relationship with Towner.

Glenn and 52-year old Doris Towner married in July 2013, and they have had an open relationship that included many sexual encounters with Keene, according to the affidavit.

Keene is being held on $50,000 bond awaiting trial, and could face up to 15 years in prison on the incest charge, up to one year in prison on the each of the child endangering charges, and up to six months in prison on the false reporting charge, if convicted.

Both Towner's have pleaded not guilty to similar charges connected to this case, and are also awaiting trial.