A District woman pleaded guilty Tuesday to involuntary manslaughter and driving under the influence, charges stemming from an incident last month in which the woman’s car jumped a sidewalk, pinned a pedestrian to a tree and killed her.

Maria N. Werts, 49, faces up to seven years in prison if D.C. Superior Court Judge Herbert Dixon accepts the terms of her plea deal. If Werts had gone to trial and been convicted, she could have been sentenced to more than 30 years.

Assistant U.S. Attorney Edward O’Connell said that about 2:45 p.m. April 28, Werts smoked crack cocaine and drank coconut vodka before getting behind the wheel of a 2010 Toyota Yaris. Werts did not have a valid driver’s license, and the vehicle tags had expired, prosecutors said. She drove down First Street SW and ran a red light at the intersection of South Capitol Street before making an illegal right turn, authorities said.

Werts then lost control of the vehicle and drove on the sidewalk where Emmajean Gainey, 58, and another pedestrian were walking, authorities said. The car struck Gainey and pinned her against a tree between the sidewalk and street, prosecutors said.

O’Connell said that Werts jumped from the vehicle and ran but that bystanders detained her for police. Werts, prosecutors said, initially denied driving the vehicle. When police arrived, officers administered several sobriety tests, which she failed. O’Connell said Werts’s blood alcohol tested at 0.09, slightly above the legal limit.

Dixon is scheduled to sentence Werts on July 26.

Prosecutors have been busy recently with fatal drunken driving cases. This month, an Annapolis man pleaded guilty to involuntary manslaughter and driving under the influence in the March hit-and-run death of Ruby Whitfield, 71, who was struck while leaving her church in the 1100 block of Florida Avenue NE.

Last year, according to statistics from the U.S. attorney’s office, prosecutors handled three fatalities involving vehicles. In 2011, prosecutors had six such cases.