The body was found about half a mile from Mathews' house.
Sherin was confirmed dead by US police on Tuesday after over two weeks of investigation. She was missing since October 7.
Mathews had previously claimed that Sherin went missing after he sent her outside their home at around 3 am on October 7 as punishment for not drinking her milk.
The 35-year-old mother, an Indian-American registered nurse, was arrested on Thursday after her attorney took her to the Richardson police station.