Defense attorneys for Jessica Tata countered she was a good person who made a terrible mistake and asked jurors to not be swayed by anger.
The jury began deliberating Tata's sentence after closing arguments in the punishment phase of her trial.
Tata could be sentenced from five years to life in prison. She was convicted last week of felony murder in the death of 16-month-old Elias Castillo.
Prosecutors said the February 2011 fire that killed Elias started after Tata, 24, left a group of children alone with a pan of oil cooking on a hot stove while she went shopping at a nearby Target store. Along with the four children who died, three were injured in the Houston home day care fire.
"That day when she made the decision to leave, she doomed them, she doomed them," prosecutor Connie Spence told jurors, calling Tata's actions "inexcusable."
During her 40-minute closing argument, Spence talked about each child who died or was injured, showing jurors frozen video images of each one on TV screens in the courtroom.
"What each mom will do to hold their baby one more time," Spence, her voice choked by emotion, told jurors as the mothers of the children sat in the courtroom and cried. "What's a child's life worth? ... What we want is justice."
Mike DeGeurin, Tata's attorney, told jurors she never intended to hurt the children, who ranged in age from 16 months to 3 years old. He said Tata should not have left the children alone but that she went to the store for the children, to get them juice.
"She called them her babies. She didn't want those babies to be harmed," DeGeurin said.
DeGeurin said Tata also mourns for the children who died and asked jurors to not decide on an excessive sentence.
"Don't let your emotions be whipped up. Don't let your anger be whipped up," he said.
Spence argued Tata was an irresponsible day care owner who had left the children she cared for alone on multiple occasions. The fire "wasn't an aberration, it was an inevitability," she said.
Tata fled to Nigeria after the fire but was captured after about a month, returned to the U.S. in March 2011 and has remained jailed since. She was born in the U.S. but has Nigerian citizenship.
Surveillance video shown during the trial showed her shopping at Target just before the fire. A former Target manager told jurors Tata did not seem to be in a hurry after realizing she had left the stovetop burner on.
Neighbors testified they heard the children crying as they tried to rescue them from the blaze. Parents of the children who died or were injured told jurors they had trusted Tata, believing she was qualified.
Defense attorneys presented expert testimony to argue that faulty kitchen equipment may have sparked the fire.
Tata still faces three more counts of felony murder in relation to the other children who died, and three counts of abandoning a child and two counts of reckless injury to a child in relation to the three who were hurt.