Jiranová entered international athletics in 2011 competing in the 2011 European Youth Summer Olympic Festival in Trabzon, Turkey. At the 2013 European Athletics Junior Championships she finished eighth in the 4 × 400 metres relay. In 2015 she reached the semi-finals at the 2015 European Athletics Junior Championships finishing seventh. During the 2017 European Athletics U23 Championships Jiranová finished eighth in the 400 metres dash and sixth in the 100 metres hurdles. In 2019 at the 2019 European Games she finished twelfth in the field of hurdlers and later in 2019 at the 2019 Summer Universiade she retired in the lead of the 110 metres hurdles after a stumble and ended up placing sixth.