[4] The following year, at the 2022 European Junior Swimming Championships, held in July in Otopeni, Romania, Jackl won the bronze medal in the 400-metre individual medley at 13 years, 261 days of age with a time of 4:47.51, finishing 1.12 seconds behind gold medalist Emma Carrasco of Spain and 0.14 seconds ahead of fourth-place finisher Lisa Nystrand of Sweden.

[8] Jackl entered to compete in at the 2022 FINA World Junior Swimming Championships, held starting 30 August in Lima, Peru, along with fourteen other Hungarian swimmers.

[10][11] Leading up to the Championships, she was highlighted by SwimSwam for one of the top five storylines to follow in girls' competition, specifically who would make the podium in the 400-metre individual medley.

[12] On the first day of competition, she ranked sixth in the preliminary heats of the 400-metre individual medley with a 4:51.48, qualifying for the evening final.

[23] Over the course of the ensuing six days, at the 2022 Hungarian Junior National Short Course Championships contested in Szeged, Jackl swam personal best times in eight b-finals for individual events (which were the only finals open to female swimmers born in 2007 or 2008, she was born in 2008), starting on day one with a b-final third-place finish in 2:16.85 in the 200-metre individual medley.