Added Rebecca: "I'm going to miss your cheeky grin and slow smiles and dimples, and the way you walked like nothing in the world was weighing you down."
Rachel's father Tony Clark said she was someone who was always determined to succeed and that she "never gave up on people".
Yesterday was a heart-breaking day for her family but they wanted to do all they could to celebrate her life. "We have had a whole week to reflect on her life. We would like to give you a few laughs at Rachel's expense now. I'm sure she would have laughed, too," he said.
During a moving eulogy he remembered Rachel as a voracious reader who embraced the Harry Potter series, reading it seven times or more. She used to walk to school reading, and once walked into a car while her head was in a book.
"Rachel had a strong sense of wiseness and moral behaviour. She never gave up on people."
Determined from a young age, she mastered skiing early and Tony Clark recalled racing her down skifields - and her letting him "win".
"She hated coming second and struggled with others who were not as determined."
Clark thanked the people of Cromwell for their support and said they should be proud of their community.
He finished his speech by saying "go with our love, Rachel".
A common theme among those remembering Rachel was her maturity, leadership and communication, an intelligent youth with a dedication to all aspects of life and willingness to "give it a go".
Her former rowing coach Maud O'Connell said: "Farewell chicken. Tie up your boat and put your oars away and rest."
The number of people attending the funeral was a mark of the respect held for Rachel and a show of support for her family, celebrant Dave Ramsay said.
After a period of reflection, during which a slideshow of images of Rachel played, her coffin was taken from the auditorium by family, surrounded by a guard of honour.
Outside, an emotional haka bade her farewell.
Tony Clark asked mourners to donate to a trust set up in Rachel's name rather than give flowers.
The Rachel Clark Memorial Trust was established to acknowledge groups who had supported Rachel. Her death has been described as a medical event.