Cheryl Ann Schoonmaker, 38, forced the two girls, aged 8 and 10, to take turns in the trunk July 1 because there was not enough room in the car, according to Curtis Schoonmaker, her ex-husband.
The woman was driving five children, including an infant, to her ex-husband's home outside Washington D.C. None of the children was injured during the trip. The girls told their father what happened the next day and he called the police.
A magistrate in Stafford County released Schoonmaker on $5,000 bail, according to the Loudoun County Sheriff's Office.
"They asked to be let out. ... It was a hot day," Curtis Schoonmaker said. Efforts to reach Cheryl Schoonmaker were unsuccessful Monday.
Three of the five girls in the car were the Schoonmakers' children. One of the other children was a family friend and the infant was Cheryl Schoonmaker's.
Cheryl Schoonmaker is scheduled for arraignment July 22. The charges each carry a maximum of five years in prison.
Curtis Schoonmaker said his ex-wife had the option of renting a larger car but declined to do so. "She claims she doesn't see the harm in it. She didn't believe any accident would result."