Courtney Fritz Pandolfi, 40, was also charged with a felony count of driving under the influence of drugs that caused an injury, as well as one misdemeanor count of driving with a suspended license, according to the Orange County District Attorney's Office. She was ordered held on $3 million bail.
It wasn't immediately clear whether she had an attorney to speak on her behalf.
Pandolfi has a long history of driving under the influence of drugs and was convicted in 2008, 2015 and 2016. She faces a maximum sentence of life if convicted on all charges.
"This was 100 percent preventable. This woman knew the consequences of driving under the influence and she did it anyway," D.A. Todd Spitzer said in a statement.
Prosecutors said Pandolfi was behind the wheel of a Jeep SUV that drove onto a sidewalk near the intersection of Katella Avenue and Bayless Street early Tuesday morning, striking Yesenia Aguilar.
Heartbroken husband speaks out after pregnant wife fatally struck by DUI suspect in Anaheim
She was walking with her husband but he was narrowly missed by the vehicle.
Her daughter, named Adalyn Rose, was surgically delivered after the crash and remained in critical condition at a hospital. In a hopeful development, the baby was breathing on her own after her respiratory tube was removed Thursday.
Aguilar, a Disneyland employee, was 35 weeks pregnant at the time of the collision.
"We are heartbroken by the tragic loss of our cast member Yesenia Aguilar and we offer our deepest condolences to her family, friends and loved ones," a spokesperson for the Anaheim resort said in a statement.
Aguilar's co-workers gathered on Thursday for a vigil in her honor, shocked by her abrupt death.
"She struggled to have a baby. I remember when she told me she was pregnant, were all excited for her. We were looking forward to seeing this new baby arrive," said one co-worker.
A GoFundMe page has been created in Aguilar's honor.
The Associated Press contributed to this report.