The year 2011 was key in Vidya's career, as she had starring roles in two commercially successful female-led films. In No One Killed Jessica, a thriller based on the murder of Jessica Lal, and co-starring Rani Mukerji, Vidya played the real-life character of Sabrina, who seeks justice for her sister's murder. Vidya was styled in men's dresses and loose-fitted clothing; several scenes were shot on location using hidden cameras, and she was pleased with the anonymity that her styling provided. Moreover, she spoke positively of her rapport with Mukerji, noting the rarity of two leading ladies within the same Hindi film. Sudhish Kamath of The Hindu took note of Vidya's ability to be "in sublime control over her emotions" and Savera Someshwar of Rediff.com added that "her hesitant body language, her faith, her helplessness, her rage, her sorrow and her gratitude all come across beautifully". Vidya earned another Filmfare nomination for Best Actress. In the same year, she made a guest appearance in the Malayalam film Urumi and a retrospective of her films was held in Australia as part of the Bollywood and Beyond festival.
Vidya is trained in Carnatic music and briefly studied the dance forms of Bharatnatyam and Kathak. Regarding her religious affiliations, Vidya said, "I am a person with a lot of faith and I have conversations [with God] all the time but I am not so religious in the conventional, organised sense". She practices vegetarianism and was listed as "India's hottest vegetarian" in polls conducted by PETA in 2011 and 2012. Her weight fluctuations over the years have been the subject of substantial media coverage in India.
In March 2011, Vidya endorsed World Wildlife Fund's Earth Hour campaign in India. She campaigned for the cause of nutrition in India for Child In Need Institute (CINI), a non-profit organisation based in Kolkata. In September 2012, Vidya visited a village in Mirzapur, Uttar Pradesh, where she participated in a campaign to promote children's education and the empowerment of women. For her attempts to empower women, Vidya was awarded the Prabha Khaitan Puraskar 2012 by the Calcutta Chamber of Commerce; she was the youngest recipient of the award. In 2012, she became the first brand ambassador of the country's sanitation programme, later renamed as the Swachh Bharat Abhiyan. Since then, she has been part of a nationwide television and radio campaign aimed to increase construction and use of toilets.