A former East Texas kindergarten teacher was sentenced to 10 years in prison Thursday after pleading guilty to seven counts of sexual assault of a child, the Lufkin Daily News reports.

Heather Robertson (Angelina County Sheriff's Office)

Heather Lee Robertson, 38, of Lufkin, in Angelina County, must also give up her teaching certification and register as a sex offender.

Robertson was arrested in April after admitting to having sex with four high school students, two of them simultaneously.

According to a news release issued by the Angelina County district attorney's office, Robertson was found to have had sex with at least six high school students between November and February.

The teacher would invite students over to her apartment, according to the report. In one case, she had a student's parents drop him off under the pretense of moving furniture.

Some students she would pick up herself and bring back to her apartment late at night, she admitted.

According to court documents, Robertson started "chatting and sexting" a student via Snapchat shortly after spring break, then invited him over to her apartment. The student then asked if he could bring a friend he was with, and Robertson agreed.

After chatting with them briefly, Robertson had sex with both of them, police records say.

Robertson didn't use protection when having sex with the students, she said, because she was unable to have children. She also admitted to police in April that she had recently begun drinking heavily and had sometimes forgotten details of the sexual encounters.

According to the Daily News, she was arrested in March on a charge of driving while intoxicated.

Robertson could have received up to 20 years in prison for each of the seven counts.