"She was prepared to serve her entire four-day sentence," The Simple Life star's lawyer says

Nicole Richie was “pleasantly surprised” to be released after serving 82 minutes of her four-day jail sentence for a second DUI conviction, her lawyer said Friday.

“Nicole was aware that most people with sentences similar to hers are booked and released in a matter of hours and she was hoping to be treated like everyone else,” attorney Shawn Chapman Holley said in a statement. “Nevertheless, she was prepared to serve her entire four-day sentence had the Sheriff’s Department required her to do so.”

On Thursday, accompanied by her boyfriend Joel Madden as well as Holley, the five-months pregnant Richie entered the jail in Lynwood, Calif., at 3:15 p.m. She was processed into the system and released at 4:37 p.m.

“Of course, she was pleasantly surprised to be released so quickly,” said Holley.

Kerri Webb, a spokeswoman for the sheriff’s department told PEOPLE that Richie “was released early due to overcrowding in the jail system. This is standard procedure for nonviolent offenders.”

Richie, 25, who’s pregnant by Madden, pleaded guilty to DUI on July 27. As part of her sentence, she also agreed to serve a three-year probation term, must enroll in an alcohol education program and was fined $2,048.

She was arrested for DUI on Dec. 11 after being spotted driving her black Mercedes SUV the wrong way on an L.A. freeway.

She was previously convicted of DUI in June 2003.