An 18-year-old woman was killed Saturday in an early morning car crash with a drunk driver on Route 44 in the Plymouth County town of Lakeville, according to police. Both cars involved in the crash were found overturned in the road, slightly east of the intersection with Millenium Circle, and Monica Demello of Middleborough was pronounced dead at the scene, according to a statement released by Lakeville police Saturday. The crash occurred about 2:09 a.m. Kathleen Allen, 23, also of Middleborough, was charged with vehicular homicide and driving under the influence. She will be arraigned in Wareham District Court on Monday. Demello was alone in a 2004 Hyundai Accent. Allen was operating a 2004 Dodge Ram pickup and was driving with a female passenger, who was taken by MedFlight to Brigham and Women’s Hospital in Boston, police said.