Tapner comes from Hertfordshire, and was educated at Downe House School, in Cold Ash, Berkshire, graduating in 2014.
Tapner has taken part in British Eventing eventing competitions, and in July 2014, she was appointed an ambassador for the British Equestrian Federation. Tapner was discovered by Storm Model Management in 2011 at the Birmingham Clothes Show Live, and soon after, at the age of 15, became the face of Balenciaga"s 2012 campaigns. Since then Tapner has appeared in campaigns for Topshop, Selfridges, Chloé, Burberry, and has been featured in Numéro, People’s, British Vogue, West, and LOVE. Tapner has walked for designers including Giles Deacon, Michael van der Ham, Todd Lynn, and Nicolas Ghesquière, and has been shot by photographers including Steven Meisel.
Tapner has been compared to fellow British model Cara Delevingne, and in February 2014, the Daily Mail referred to Tapner as being "tipped to be the next Cara Delevingne".