This was followed by victories in the Czech National Championship in 2014 and 2015, this time in the Young Riders category, riding a horse called Bacara de la Ferme Blanche.
In 2015 and 2016, Kellnerová represented the Czech Republic at the Nations Cup and European Young Riders Championship in Millstreet, Ireland.
In 2016 she finished second in the year-long ladder of the PAVO Equestrian Cup in the senior show jumping category.
Along with Aleš Opatrný she is a member of the Berlin Lions team, and she has competed at the prestigious Global Champions League since 2017.
[3] In 2018, Kellnerová continued to compete for the Prague Lions team at the Global Champions League series, along with her teammate Aleš Opatrný.