Gwinn started playing football at the age of eight years for TSG Ailingen and later for VfB Friedrichshafen. In 2009, she began a five-year spell at FV Ravensburg. She then played a season for the B-Juniors of SV Weingarten, as the only girl in the team.
Gwinn has represented Germany on the under-15, under-16 and under-17 national teams. At the age of 13 years, she was called up by coachBettina Wiegmann for under-15 national team training in November 2012. She made her debut for the U-15 national team in April 2013, a substitute in an 8–0 win over the Netherlands. She made three appearances for the under-16 national team in 2014. In 2015, she was the youngest player in the U-17 national team squad for the European Championship in Iceland where the team reached the semi-finals but were defeated 0–1 by the Swiss selection. UEFA's technical report noted that Gwinn's pace on the right wing had been a positive feature of Germany's play. In May 2016, the team won the 2016 UEFA Women's Under-17 Championship after a penalty shootout against Spain in Belarus. The four Freiburg players in the squad contributed seven of Germany's 10 goals at the tournament and two of them, including Gwinn, successfully converted their kicks in the shootout. At the 2016 FIFA U-17 Women's World Cup in Jordan, Gwinn helped Germany beat Venezuela 2–1 in their opening match earning her the "Player of the Match" award. She scored the first goal with a volley, then assisted on the second. Entering the tournament with 23 Under-17 caps and as a first team player with Freiburg, Gwinn was considered one of the pillars of the team. In the Germans' second match against Canada, Gwinn's direct free kick salvaged a 1–1 draw. In the third match, Gwinn scored a goal in Germany's victory over Cameroon. She played in the 2017 UEFA Women's Under-19 Championship in Northern Ireland where she reached the semi-final and with this she qualified for the 2018 FIFA U-20 Women's World Cup.
Senior
On 14 May2019 Gwinn was named to the 2019 FIFA Women's World Cup German squad. In her FIFA Women's World Cup debut, she secured the win for Germany in their opening game of the 2019 FIFA Women's World Cup by scoring the only goal in a 1–0 group-stage victory over China. She was named "Player of the Match" for her contribution. The GermanWorld Cup campaign ended in the quarterfinals after a 2-1 loss to Sweden. Gwinn was later awarded with the Best Young Player Award for her performance at the tournament.
International goals
Scores and results list Germany's goal tally first: Source: