The children’s bodies were found in the bathtub of her home Wednesday evening, the New Orleans Police said in a statement.
The mother, identified as Chelsea Thornton, 23, admitted to officers that she killed the young children, police said.
After the killings, she said she boarded a bus to a nearby hospital.
Thornton faces first degree murder charges.
A relative of the children’s father was outside the apartment Wednesday as detectives worked inside.
There is “no reason for this. I just wish that we could have helped her and helped them,” Nicole Hammons told CNN affiliate WDSU.
Hammons said the father of the children had an off -and-on relationship with Thornton.
“He tried to help her and help their kids, and other family members also tried to help her. You can only go so far,” she said.