HILLSBORO, Mo. (AP) — A St. Louis-area woman who caused a wreck that killed an expectant mother and her unborn twins has been sentenced to 30 days in jail — plus the holidays.

Sharon Foster, 40, was sentenced Monday in Jefferson County for the Christmas Eve 2008 accident that killed Kim Farrar and her unborn girls.

Authorities say Foster was speeding when she struck the Farrars’ car head-on. James Farrar, Kim’s husband, survived.

Both the prosecutor and defense attorney described Judge Gary Kramer’s sentence as unique: The next 30 days in the county jail, plus three- to five-day stints for every holiday through 2014.

Kramer says the intent is to get drivers to be more careful on the roads, especially over the holidays.