According to police, Laxmi N Patil (50) and her 17-year-old daughter Padma, residents of Sativali in Vasai, would frequently quarrel over petty issues.
On Saturday night both of them had a quarrel and the girl left her home on Sunday morning.
However, concerned about her daughter, Laxmi started looking for Padma and reached the lake near Gaondevi temple, where she spotted her belongings lying scattered, police said.
Presuming that Padma had committed suicide, the distressed woman also ended her life by jumping into the same lake, police said.
Their bodies were later fished out by the local fishermen and were sent for the post-mortem.
A case of accidental death has been registered in this regard and further investigations are on, police added.