A former employee at an alternative school in North suburban Gages Lake has been arrested on allegations she had an inappropriate relationship with a 15-year-old student while she worked there, authorities announced Thursday.

Sandra J. Pardo, a former paraprofessional at Cyd Lash Academy, is charged with three counts of aggravated battery, solicitation to meet a child and child endangerment.

Pardo, 38, of the 100 block of Glen Street in Grayslake, was arrested Wednesday after a two-day investigation by Lake County sheriff’s detectives. Pardo had resigned Tuesday, a day after the investigation began, said Tim Thomas, interim superintendent at the Special Education District of Lake County.

The investigation began after police learned of a video on social media depicting the boy driving a car while a woman who sounded like Pardo spoke from a passenger’s seat, sheriff’s Deputy Chief Chris Covelli said.

Pardo and the boy began having an inappropriate relationship last month, Covelli said. Pardo gave the boy a massage and kissed him, police said.

During a court appearance Thursday morning, Pardo was ordered to be held in jail until a Feb. 11 detention hearing.

The case remains under investigation. SEDOL officials are cooperating with police, Thomas said.