Esteysi Izazaga Sanchez, who goes by Stacy, was ordered held on $1.5 million bail.
Deputy District Attorney Aimee McLeod called the defendant "a great danger to the public.''
The prosecutor said 69-year-old Jack Ray Tenhulzen was walking along the 4000 block of Mission Avenue about 6:30 a.m. Monday when Sanchez hit him so hard that it stripped him of some of his clothing.
Sanchez, 29, drove for at least a half-mile with the victim's body partially inside her Pontiac sedan and his detached leg on the trunk of her car before pulling into a cul-de-sac on Magdalena Drive, authorities said.
The defendant ran to her home -- located about a block away -- and was arrested by police an hour later, the prosecutor said. Sanchez still had shards of glass in her hair when she was taken into custody, McLeod said.
Sanchez had a blood-alcohol content of between .18 and .19 percent -- well above the legal limit of .08 -- and told police that she drank twice that night, McLeod told reporters.
Customs officials have placed an immigration "hold'' on Sanchez, who was no prior criminal record, McLeod said.
In addition to gross vehicular manslaughter and hit-and-run, Sanchez is charged with two DUI counts and driving without a license. She faces 15 years and six months in state prison if convicted.
A preliminary hearing was set for Aug. 9.