Rhonda Tavey said she kidnapped the children because their biological mother had threatened her life.
Houston authorities had issued an Amber Alert earlier Wednesday in connection to the abduction of the Houston children. The Harris County District Attorney's office charged Tavey, 44, with five counts of kidnapping.
Tavey, who is white, said all she ever wanted was to do God's will and that she also took the children, who are black, for their own safety. She said their mother, Erica Alphonse, was "abusive."
Tavey said last month she found her bank statements in the purse of Alphonse, whom she had opened her home to after the Louisiana family was devastated by Hurricane Katrina three years ago.
"When I confronted her with that, she pulled a knife and threatened to kill me. That's when I made arrangements to get the kids out," Tavey said Thursday in an online edition of the Houston Chronicle.
"Erica is trying to make herself out to be a wonderful mom," Tavey said. "She is abusive. I've seen her punch the boys ... because they're boys,'" she told the newspaper.
The newspaper reported that Alphonse denies pulling a knife on Tavey and said Tavey is lying to damage Alphonse's reputation.
In an interview with KHOU-TV Alphonse pleaded to Tavey for her children's return. "Rhonda, I'm saying this from the heart: you've been our family for three years," Alphonse said. "You've grown accustomed to loving my children and loving me. I've grown accustomed to loving you. I never thought you would do this to me."
Tavey is likely in the Dallas area, investigators believe since she gave an interview to a local television station there, KHOU reports.
The women said they worked out an agreement after meeting in Reliant Park, where Tavey had been volunteering for the American Red Cross after the hurricane. Their arrangement called for Tavey, who has two teenage daughters, to care for Alphonse's two boys and three girls who are ages 3 to 8, while Alphonse sought work to become self-sufficient.
Alphonse, calling Tavey her family's "guardian angel" after Katrina's devastation, said she told Tavey she wanted to return to her New Orleans hometown eventually, even though Tavey prayed they would remain in Houston.
Alphonse said she returned to New Orleans two years ago and left the children in Houston. She returned this summer and their arrangement turned sour, culminating in the charges against Tavey.
"I had gotten her a job, a car, set her up in an apartment," Tavey said. "I'd helped her do all that when she decided she needed to go back."
Harris County District Attorney's office spokeswoman Donna Hawkins told The Associated Press constables had contacted Tavey's attorney before filing charges against her on Monday but the woman refused to return the children.
The children are identified as:
Tavey is believed to be driving a blue 2004 Chrysler Town and Country Van, Texas License: 963-PTB. Officials say Tavey may be in the Dallas-Fort Worth areas.