The woman and her 11-year-old daughter died during medical treatment, while condition of her two daughters and four-year-old son are said to be critical, police said.
Pravesh Sharma and Shikha died after consuming the poison, they said.
According to police, Pravesh's husband Munesh Sharma works as peon at a nearby private school and he was a habitual alcohol drinker.
"Pravesh used to often have fights with Munesh over his alcohol habit. Last night, she had a scuffle with him when he came back home in an inebriated condition," a senior police officer said.
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After eating noodles, the health condition of the five started deteriorating and their neighbours rushed them to the nearby Sarvodaya Hospital, where Pravesh and Shikha succumbed.
Condition of Sakshi, Seema and Anmol is said to be critical, the officer said.
Police have sent the bodies for postmortem examination and further investigation is on, officer said.