Montgomery County authorities on Friday arrested an Upper Dublin High School teacher who allegedly exchanged sexually explicit text messages with a special-education student, and gave her a vibrator at the school and urged her to masturbate with it.

Cheryl Bremble, a 40-year-old special-education teacher, "encouraged the juvenile to use the device on numerous occasions during text-message conversations," said Montgomery County District Attorney Risa Vetri Ferman and Upper Dublin Police Chief Terrence Thompson.

Ferman called the crime "particularly repulsive when you consider the fact you're dealing with a vulnerable child in the special-education program."

Bremble, a divorced mother of two who lives in Hatboro, was charged with child endangerment, corruption of a minor, and unlawful contact with a minor. She could not be reached for comment.

Upper Dublin Superintendent Michael Pladus said that Bremble, a teacher in the district since 2000, had been suspended, and that the district had taken "all the necessary actions" to notify parents. He declined to elaborate other than to say the district was cooperating with investigators.

"Any allegation of improper communication or solicitation involving a member of our faculty or staff will absolutely not be tolerated," he said.

Prosecutors did not identify the alleged victim. They said Bremble had spent "a lot of time" with the girl outside school, including shopping trips on which she bought her gifts.

They say Bremble and the girl had sexually explicit conversations "in person and via text messages." She also allegedly gave the girl the sex device on the high school campus during school hours and encouraged her to use it "on numerous occasions during text-message conversations."

Ferman said investigators had no evidence of other victims. She urged the public to report any information that might pertain to the case.

Bremble had been a reading teacher in the high school's learning-support program for 11 years, according to a resumé she posted online. Before that, she worked briefly in the Centennial School District.

On the website RateMyTeachers.com, one anonymous student rated her in March as average. "Acts like a teenager," the comment said.

She was arraigned Friday before District Judge Patricia Zaffarano in Ambler and released on $25,000 bail.

Her divorce was finalized only in recent weeks, according to her former father-in-law, Thomas Bremble Sr. He said his son, Thomas, and former daughter-in-law share custody of two children, ages 12 and 5.

Thomas Bremble Sr. appeared stunned by the news Friday.

"It shocks the bejesus out of me," he said.

Contact staff writer John P. Martin at 215-854-4774 or jmartin@phillynews.com.