Margarita Gonzalez received a 25-year sentence for the 2008 apartment building fire on the Northwest Side.
Her boyfriend, Rafael Polanco, was sentenced to more than 17 years in prison.
The badly burned girls gave emotional statements in court Friday, with one of them asking the judge to put them away "until they have no more birthdays."
The fire was set to get revenge against the children's mother. Gonzalez was jealous of her.