35-year-old Vimla hanged herself from the ceiling this morning, SHO Neem Ka Thana Rajiv Rahr said.
When her body was shifted to a local hospital for post-mortem, her younger sister Maya (28) also committed suicide, he said, adding that reasons of the suicides are not clear.
Her mother-in-law and children were present in the house when Maya committed suicide, the SHO said.
"Vimla's husband was in the Army and had died on duty in Punjab some nine months ago while Maya's husband is a driver," the SHO said.