Parveen Bibi told a court in Lahore, Punjab that she killed her daughter "for bringing shame to her family," police spokeswoman Nabila Ghazanfar told CNN Tuesday.
Parveen's son Ahmer Rafique was sentenced to life in prison for his role in the crime.
Rafique had been living with her new husband for a month before she visited her home in Lahore in the hopes of a reconciliation with her family.
But when Rafique arrived, her mother and brother tied her to a bed, poured gasoline and set her on fire, police said.
Parveen then turned herself over to the authorities but expressed no sorrow for actions.
New law
Previously, murderers were able to walk free in many instances, creating what critics characterized as a culture of impunity. Now, a killer will face a minimum sentence of 25 years in jail.