Kasur police have arrested the accused father and are investigating the incident.
The firing incident was reported in the Hasan Khel area of the Tank district.
The victims were identified as Shakeela Kafil and Kafil Babar, resident of Gulshan-e-Ravi area of Lahore.
A woman killed second wife of her husband and then committed suicide in one of the incident.
The accused opened fire on his family members, killing his paternal uncle and a cousin.
In a horrific incident, a man has allegedly killed his mother, brother and sister-in-law over a domestic dispute in Lahore on Sunday.
Raids being conducted to arrest the culprit, the police said.