Ebony Wilkerson, 32, is being charged with three counts of premeditated attempted first-degree murder and three counts of child abuse, the Volusia County Sheriff's Office announced Friday.
Police initially stopped Wilkerson on Wednesday after her sister reported she had left the house with the children and was "talking about demons." Officers said she appeared lucid during the traffic stop, and told them she was afraid her ex-husband was going to harm her and the kids.
Two hours later, witnesses in Daytona Beach, Fla., saw Wilkerson drive her van into the ocean.
"She told them 'close your eyes and go to sleep,' she was taking them to a better place,'" said Sheriff Ben Johnson.
Officers and bystanders rescued the children, ages 3, 9, and 10, just before the vehicle became completely submerged.
"The two in the back seat was crying, with their arms out saying 'Our mommy's trying to kill us, please help,'" Tim Tesseneer, one of the first witnesses to reach the van, told WESH.
"The kids are like, 'No there's a baby. There's a baby,'" Tesseneer said. "She (the mother) wouldn't say a word. She didn't tell us nothing about a baby."
The sheriff's office says Wilkerson was hospitalized for mental evaluation. The officers who initially stopped her said they suspected mental illness, but couldn't detain her because she didn't seem to be a danger to herself or others.