Police have said that no-one else was involved in the death of student Caroline Everest.
The body of the 18-year-old Sheffield Hallam University student was discovered in a river in the city on November 24 and a 31-year-old man who was arrested on suspicion of rape has been released with no further action.
South Yorkshire Police, who are still working to determine the circumstances of her death, have ruled out the actions of another person as the cause.
The family of Miss Everest - who was known as Carrie - said they are living out "every parent's nightmare" as they wait to find answers about how their "treasured, perfect daughter" died.
In the statement released through the police, they said: "Carrie was a thoughtful girl and she cared deeply about her friends and family. She tried so hard to organise her life and the things she wanted to do. She was a young woman with such a strong appetite for living and participating in everything she did.
"Her friends, colleagues, fellow students, all appreciated her willingness to help others, to do everything she could do to make a difference."
Miss Everest was reported missing after leaving a Sheffield nightclub in the early hours of Sunday morning, two days before her body was found.
Her family, who live in the north of Sheffield, became worried when she did not turn up for work or a family dinner on Sunday.
The family statement added: "For her mum and dad, for her brother and sister, for the extended family of which she was so integral a part, there is a deep sense of loss that is so very, very painful.
"Caroline gave us so much pleasure and she was so loved, so treasured, that we will carry her memory with us every minute of every day for the rest of our lives.
"Carrie was a very precious young woman, enthusiastic and caring, loving and genuine. She was always thinking of others and how she could help them.
"Her radiant smile, marvellous sense of humour and warm-hearted nature made her the perfect daughter, a girl who had so much to give and so much to live for.
"She is now dancing through eternity. Fly high little star."
Miss Everest had loved every style of dancing and joined the City Limits dance centre when she was four years old.
She enjoyed the performances, shows and exams and was training to compete in a ballroom competition, her family said.
She was the sort of person who made "an impact on everyone she had ever met" from nursery to Walkley Primary and Junior School, through to City College and Sheffield Hallam University, they said. She had also been a volunteer at a Barnardo's charity shop.
Anyone with information about her death should call South Yorkshire Police or Crimestoppers anonymously on 0800 555111, quoting incident number 998 of November 22 2015.