The hashtag #JusticeForUwa is trending in Nigeria, with her family appealing for help to track down her killers.
Uwavera had been studying in a "quiet" church near her home in Benin City when she was killed, her sister, Judith, told BBC Pidgin.
The student, who had wanted to become a nurse, died in hospital on Saturday, three days after the attack.
Judith Omozuwa said her sister had also been raped.
Her family said they received a call from a woman at the Redeemed Christian Church of God on Wednesday evening.