Career
She began her career at the age of 13. She participated for the first time in a World Cup in 2012. In Houffalize and Louisiana Bresse she finished second place in the top 10.
She was born in Wierden, Netherlands.
Kalvenhaar died in Grenoble, France, due to an accident during a UCI World Cup XCE race in Méribel, France. She fell during the XC-eliminator, a mountainbike race where 4 participants race a short track.
She fell hard on a bridge, and was taken to hospital by helicopter, where she died the next day.