Sonia's breakthrough role came in 1997 with the Tamil film "Gnanapazham," directed by Agathiyan. Her performance earned her a nomination for the Tamil Nadu State Film Award for Best Actress. She then went on to star in films like "Sandhalvathiyin Aadhi" (1998), "Pudhu Kudathiyil" (1999), and "Kadalir Kadhirvelan" (2000).