Gruber comes from Latzfons and is part of the South Tyrolean national team. She started in the Intercontinental Cup for the first time in the 2007/2008 season and achieved third place overall with several victories and podium places in winter 2008/2009 and second overall in winter 2010/2011. At her first international junior championship, the 2009 European Junior Championship in Longiarü , she finished in fifth place. Two years later, the student at the Oberschule für Soziale in Brixen won the silver medal behind Evelin Lanthaler at the European Junior Championships 2011 in Laas .
At the beginning of the 2011/2012 season , Gruber first took part in a World Cup race in her home town of Latzfons. It reached fourth place straight away, but was no longer used in the World Cup as the season progressed. She could not qualify for participation in the 2012 Junior World Championship.