The woman, 20, told the BBC that four men carried out the attack in northern Haryana state two weeks ago. She denied consuming beef.
She said the men beat her uncle and aunt to death in their home in Mewat.
Many Hindus consider cows sacred and the slaughter of the animal is banned in several states, including Haryana.
The suspects have been arrested and charged with rape and murder.
However police have told reporters that there is no evidence to suggest that cow protection groups were involved in the attack.