Puchner comes from St. Johann im Pongau in the province of Salzburg . In the school class she not only achieved numerous victories at regional events, but also some successes at national and international level. In 2005 and 2006 she was twice Austrian school champion in the Super-G and from 2005 to 2007 she achieved four second places at the Austrian school championships. During these years she was also successful in the most important international school races, the Trofeo Topolino in Italy and the Whistler Cup in Canada. At the Trofeo Topolino she won one silver and two bronze medals and at the Whistler Cup one gold medal in the Super-G 2007 and two bronze medals.
Until she was 14, she was also considered a great tennis talent and played in tournaments at local level in the summer. However, she opted for alpine skiing. From December 2007 Puchner competed in FIS races , a year later she won her first Super-G victory in Haus im Ennstal . In January 2009 she became Austrian youth champion in giant slalom and combined in her age group. The next month she won the gold medal in giant slalom at the European Youth Olympic Festival in Szczyrk . After these achievements, Puchner was accepted into the B-team of the Austrian Ski Association in 2009 . At the Austrian championships in 2010 she won the bronze medal in the super combination.
In March 2010 Puchner took part in the European Cup for the first time . At the beginning of next winter she reached her first podium as third in the Kvitfjell Super-G . In addition to another third place in the downhill from Sochi , she achieved a total of seven top 10 placements in the 2010/11 season , making her sixth in the Super-G and seventh in the downhill classification. At her first Junior World Championship in Crans-Montana , she finished 13th in the Super-G and 18th in the downhill. A year later, at the Junior World Championships 2012 in Roccaraso, she had two eighth places in the giant slalom and her best results in the combination. In the European Cup she stayed in the 2011/12 season in contrast to the previous year without a podium. Her best result was a sixth place on the downhill from Sella Nevea . At national level, she became Austrian youth champion in downhill in her age group Youth II in 2012 , while she came second twice and third once at the state championships in 2012 .
On January 12, 2013, Puchner made her debut in the World Cup . She finished 47th in the downhill from St. Anton . For the first time in the World Cup points she drove on December 21, 2013 as 29th of the descent from Val-d'Isère . On January 13, 2014, she won her first European Cup race with the Super-G in Innerkrems . She celebrated her first World Cup victory on March 16, 2016 in the downhill at the World Cup final in St. Moritz . There she was seriously injured almost a year later, on February 8, 2017, during downhill training during the Alpine World Ski Championships . In the fall, she suffered a fractured tibia and fibula in her right leg. On March 13, 2019, she surprisingly achieved her second World Cup victory at the Downhill World Cup final in Soldeu in windy conditions.