According to HPD spokesperson Kese Smith, one of the woman's friends spotted her throwing things out of her house into an adjacent field on Sunday morning.
Authorities say she told the man she had to move Sunday and asked him to help her move. As they packed her belongings, he asked about her children, wanting to know where they were. She reportedly told him she had killed them.
The man didn't take her comments seriously at first. After he was done helping her, he asked again about her children. He says she then repeated that she had killed them.
The man then drove with the mother and parked about a block away from an HPD station, police say.
He told the woman he had to do something and left the vehicle. He then ran to the police station and reported the woman's comments to authorities.
The mother, whose identity has not yet been released, was taken into custody, but has not yet been charged. She was not at the scene, but was able to tell officers where the children were.
Investigators then located the bodies of the two children, a 7-year-old boy and a 5-year-old girl, underneath the house next door. She allegedly drowned them in the bathtub on Friday.
She also has a 12-year-old son, but he was not home at the home and safe with his father.
The mother is 30 years old with no history of mental illness.
Police say she has a minor criminal record, but didn't go into detail.