Born in Tanzania, to a German father and a Tanzanian mother, Baum's family relocated to Germany when she was just four years old. Her passion for football had already been established before that, with her regularly playing with her older brother, Dennis, who tragically passed away in a car accident at the age of 17.
Baum honours his memory every time she steps onto the pitch now, with his initials on her boots and tape on her wrist bearing his name and a quote. "That way, he's always with me," she toldDie Welt. "I wish he was here and could see everything I do."
Upon moving to Germany, Baum started playing for local club MTV Ahrensbok before moving on to TSV Pansdorf, where she was the only girl. The club would soon share her services with Hamburg, whose youth academy she joined as a teenager. In August 2022, when she was still just 15 years old, Baum signed a first-team contract with HSV, tying her to the club until 2025.
The teenager would depart when that deal expired, to join RB Leipzig on a free transfer, but she played a huge part in helping to get Hamburg into the Frauen-Bundesliga, for the first time since 2012, in those three years. Her first season saw promotion to the second-tier and Baum also helped the club reach the semi-finals of the DFB-Pokal, in the same year as promotion to the top-flight.
As she rose up through the ranks in the senior club game, the tricky forward was also establishing herself in the youth national teams in Germany. Playing in the Under-16s as a 14-year-old, the U17s as a 15-year-old and featuring in all five games as her nation reached the quarter-finals of the U20 World Cup, aged 17, Baum has been playing regularly with the U23s in recent months, despite still being just 19 years old.