She was born on 16 May 1934 as the eldest daughter of eminent Sanskrit scholars O M C Narayanan Nambudiripad and Uma Antharjanam in Vellinezhi (Palakkad District, Kerala, India). Sumangala has been a prolific writer of books for children over the past 40
years. 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 wrote a song for the Malayalam film Chenda.
She was married to Desamangalam Ashtamurthy Nambudripad (he died in 2014) and had three children – Usha Nambudripad, D. Narayanan and D. Ashtamurthy. As Leela Nambudripad, she served in the Public Relations Department of Kerala Kalamandalam for 22
years. Sumangala resided in the town of Wadakkancheri in Thrissur District.