[1] From Aremark,[2] Jæger was 14 years-old when she came third at the Norwegian senior indoor championships over 200 metres, in February 2018.

[3] As a 14 year-old at the Baltic Athletics Championships in 2018, she broke the Norwegian record for girls aged 15 in the heptathlon, that had stood since 1986, with a score of 5352 points.

[8] Jæger finished in fourth place in the 400 meters at the 2022 World Athletics U20 Championships held in Cali, Colombia with a time of 52.23 seconds.

[9] Competing at the 2023 European Athletics U23 Championships held from in July 2023 in Espoo, Finland, she won a silver medal in the 400m after a close battle with Yemi Mary John, with Keely Hodgkinson in third.

[19] She qualified for the final at the 2024 Summer Olympics over 400 metres in August 2024, finishing in eighth place.