Fondly referred to as the Enid Blyton of Malayalam, Sumangala has penned 37 books of which 23 are for children. Her most celebrated works include Mithayippoti, Neypaayasam, Manchaatikkuru, Kurinjiyum Koottukaarum, Ee Kattha Kettittundo, Nadodi Cholkathakal, Rahasyam and Kudamanikal. Perhaps her most famous work is a translation into Malayalam of the Panchatantra. Sumangala has also translated the Valmiki Ramayanam into Malayalam from Sanskrit. Another important literary work of hers is the compilation of Pacha Malayala Nikhandu. Sumangala is the recipient of many awards including the Kerala Sahitya Akademi Award for the best work in children's literature (in 1979) and the Bala Sahitya Institute award for Lifelong contribution towards children's literature (in 1999).
She is married to Desamangalam Ashtamurthy Nambudripad and has three children - Dr. Usha Nambudripad, D Narayanan and D Ashtamurthy. As Leela Nambudripad, she has served in the Public Relations Department of Kerala Kalamandalam for 22 years. Sumangala resides in the town of Wadakkancheri in Thrissur District.
She has also written a book called "Kerala Kalamandalam History" as well