Van Alphen grew up in Bladel, in North Brabant, and came through the Dutch cyclo-cross scene rather than the road. She was second in the under-23 race at the 2021 world championships in Ostend, four seconds behind Fem van Empel, with Kata Blanka Vas third. Her move into the elite front rank took several winters longer than van Empel's.
She has raced road and cross in parallel since turning professional, with the road as the secondary programme and the winter the stronger half of her year. She reached no World Cup podium in the 2021-22 or 2022-23 seasons, and spent them in the second rank of a Dutch field that was winning almost everything.
She took bronze at the European championships in Middelkerke on 8 November 2025, fifty-six seconds behind Inge van der Heijden, with Lucinda Brand between them. She won the World Cup round at Flamanville on 30 November ahead of Amandine Fouquenet, the first World Cup victory of her career, and took over the series lead. Flamanville was the only one of the twelve rounds that winter not won by Brand, Puck Pieterse or Ceylin del Carmen Alvarado.
Van Alphen was second behind Brand at Terralba and at Namur, and third at Antwerp on 20 December, where Brand took back the series lead and went on to win it ahead of van Alphen and Fouquenet. She reached no World Cup podium after Christmas, and at the world championships in Hulst on 31 January 2026 she finished fourteenth, two minutes and nineteen seconds behind Brand.
In the Superprestige she won the overall title without winning any of the eight rounds, reaching the podium at Overijse, Niel, Merksplas and Heusden-Zolder across October, November and December. Fouquenet won three rounds that winter and finished second in the series, with van der Heijden third. The competition ran to a final round at Middelkerke on 7 February 2026.









