Prabha Bannabilaya was the Princess of Siam (later Thailand). She was a member of Siamese Royal Family.
She and her sister were the only twin couple of Chulalongkorn, King Rama V of Siam. and Chao Chom Manda Phrom (daughter of Phraya Phitsanuloka Thibodi). She had 3 siblings, 1 elder sister, 1 younger brother and 1 younger sister.
Princess Prabha Bannabilaya and her sister Princess Prabai Bannabilas were the 4th twin couple in Chakri Dynasty. The former 3 twin couples died ot long after birth.