She first came to attention when she represented India at the 1997 Miss World pageant and won the crown at 24. An Anglo-Indian, she comes from parents who are separated, but her family was still very close-knit. As a teenager, she was a tomboy, tall and gangly. She went to St.Anns High School, Secunderabad . she graduated from Osmania University in English through correspondence. Before modelling she even worked for a Event management company, Encore. She then worked as a Public relations office BMG Crescendo where she managed careers for Anaida and Mehnaz . It was Anaida who forced her to send her pictures for the Miss India Contest and the rest is history. She was the third Indian miss world after Reita Faria and Aishwarya Rai.

Diana also hosts a popular show on the History channel called "Biography".