Kristen Barnett (Boulder County Sheriff's Office)

A 38-year-old preschool teacher in Nederland was arrested Thursday on suspicion of sex assault on a child by a person in a position of trust after a young girl told her parents that her teacher touched her private parts during naptime, according to court documents.

Kristen Carol Barnett, who has been a teacher at Over the Rainbow preschool in Nederland since the summer of 2009, turned herself in at the Boulder County Jail about 8 a.m. Thursday, according to sheriff's Cmdr. Rick Brough.

The mother of the victim -- who is a student at the preschool -- contacted the Sheriff's Office on Dec. 10 to report her suspicions that a teacher at the school had sexually assaulted her child, according to Brough.

According to an arrest warrant, the young girl was at home and lying down for a nap when she asked her mom to "rub her butt," the warrant said. The girl said she wanted her mom to rub "inside like Kristen does," according to the warrant. The child then demonstrated by rolling onto her back and spreading her legs, the warrant said.

The child said her teacher has done the same things to other children at the school, according to the warrant. When questioned by a counselor, the girl said the touching makes her "not feel right," the warrant said.

She said the touching happened "lots" of times, and it was always over her clothes. Investigators tried several times to interview Barnett about the allegations, but she didn't return their phone calls, according to the warrant.

Throughout the investigation, authorities received calls from Nederland residents wanting to "comment about Kristen Barnett's character," according to the warrant.

"While the majority of the callers were accusing Kristen of being dishonest and having questionable ethics, none of them could offer any evidence of other children having been assaulted by Kristen," according to the warrant.

One woman told investigators she knows Barnett from a Bible study and described her as "silly and fun," according to the warrant. The woman did concede that "several children had left the school because of Kristen working there," the warrant said.

Barnett's husband, Kirk Barnett, is on Nederland's Board of Trustees, according to the warrant. He couldn't be reached for comment Thursday night. Repeated calls to Over the Rainbow preschool were not returned. Barnett's name no longer is listed as a staff member on the school's Web site.

Barnett was released from the Boulder County Jail on Thursday after posting a $1,000 bond.