MORGAN HILL — A preschool teacher faces jail time after pleading no contest to misdemeanor charges stemming from dosing the sippy cups of her young charges with sleeping pills.

Deborah Gratz, a 59-year-old Hollister resident, entered the pleas this week on five counts of attempted child endangerment, according to the Santa Clara County District Attorney’s Department.

“This is a case about betrayal,” said prosecutor Sumerle Davis. “Ms. Gratz betrayed the parents and the trust of these innocent children who look up to their teachers for every need, from their ABCs to quenching their thirst.”

Gratz had worked at the Kiddie Academy in Morgan Hill since 2007, employed as the “lead toddler teacher” in the mornings. She watched over about 10 children ages 1ï»¿ and 2.

A co-worker saw her putting something into the cups and, upon inspection, staff members found residue in five of the vessels. It happened early in the morning as teachers prepared for the day, and the cups were confiscated before any kids used them.

Gratz was fired the same day, although the school came under fire from parents and was criticized by police for not notifying authorities immediately. She was arrested March 11, a Monday three days after the incident occurred.

Sumerle said Gratz admitted to police that she dosed the cups with crushed Sominex, a sleep aid that is also used for allergies, cold relief and motion sickness. Sominex labeling advises it not be used for children under 12.

Sumerle said Gratz told police that she did it so the kids would sleep longer during naptimes.

Gratz had originally faced an additional five counts of assault when she was charged in March and, at that time, prosecutors said she could face more than two years in jail if the sentences ran consecutively. However, that was considered unlikely. Gratz is scheduled to be sentenced July 5.

Contact Eric Kurhi at 408-920-5852. Follow him at Twitter.com/erickurhi.