Shurpanakha was the youngest child of rishi Vishrava from his second wife Kaikeshi. She was sister of Raavan. She was very beautiful and was called Minakshi (one who has eyes like fish).
She fell in love with a Danava prince of Kalakeya clan named Vidyutjihva/Dushtabudhi and married him against the wishes of her brother Raavan.
Once after conquering the underworld Raavan was visiting his sister’s place and got into an argument with Vidyutjihva and killed him. Nobody had the power to confront Raavan.
Minakshi was distraught but she also couldn’t do anything. She became Shurpanakha and started roaming in the woods with her relatives Khar and Dushan but she could never forgive her brother for making her a widow and killing the person she loved.
Some narratives suggest that Shurpanakha deliberately instigated Raavan to kidnap mata Sita because she was convinced that only Shri Ram was capable of killing Raavan and take revenge from her brother for making her a widow.