Devadarshini's parents are both retired principals; she has a sister. She studied commerce in college and pursued a master's degree in Applied Psychology some years later. In 2002, Devadarshini got married to Chetan, who is a popular television actor as well. Devadarshini and Chetan met and worked together for the first time in Marmadesam. She gave birth to a girl child named Niyati in December 2003. While still in college, she began anchoring television shows. She was then offered an opportunity to act in the Doordarshan serial Kanavugal Ilavasam, which led to her landing a role in the successful mystery series Marmadesam by Naga. Devadarshini became part of the series' second installment, Vidathu Karuppu, which she considers a "big turning point" in her life as it established her in the industry. Following her marriage in 2002, she began to receive film offers as well. The first project she signed was Enakku 20 Unakku 18 directed by Jyothi Krishna, although Gautham Menon's action drama Kaakha Kaakha released first. Parthiban Kanavu that released the same year won her the Tamil Nadu State Film Award for Best Comedian. She played the lead role in Sakthi Pirakuthu, a film made by an NGO.