The sisters were born to Akkarai Shri S Swamynathan and Smt A Janaghi in Nagercoil, a small town in southern Tamil Nadu. They grew up in an environment teeming with music; their grandfather Suchindram Shri S P Sivasubramaniam was an eminent vocalist, violinist, and composer, and their grandmother Smt R Sornambal was a music teacher and Harikatha exponent. Their father and guru, Akkarai Shri S Swamynathan, who worked with the Indian Bank as manager, is also a renowned violinist and highly sought-after teacher.

Coming from a rich musical lineage, the sisters showed a lot of promise, even as toddlers. Observing this, Swamynathan ensured that they were always immersed in music and began intensively training Subhalakshmi, the elder of the two, initially in vocal music. When she was four he did not hesitate to send her on an overnight bus ride from Chennai to Nagercoil to spend quality musical time with her grandparents. There, Subhalakshmi performed with her grandmother at one of her Harikatha concerts, and instantly won the hearts of all. As he trained Subhalakshmi, her younger sister Sornalatha keenly observed everything, and she proved sharp enough to quickly grasp the musical knowledge that was imparted to her sister.