Youth

Gwinn has represented Germany on the under-15, under-16, under-17, under-19 and under-20 national teams. At the age of 13 years, she was called up by coach Bettina Wiegmann for under-15 national team training in November 2012.^[8] She made her debut for the U-15 national team in April 2013,^[9] a substitute in an 8–0 win over the Netherlands.^[10] She made three appearances for the under-16 national team in 2014.^[11] 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.^[12] UEFA's technical report noted that Gwinn's pace on the right wing had been a positive feature of Germany's play.^[13] In May 2016, the team won the 2016 UEFA Women's Under-17 Championship after a penalty shootout against Spain in Belarus.^[14] 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.^[15]

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.^[16] She scored the first goal with a volley, then assisted on the second.^[17] 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.^[18] In the Germans' second match against Canada, Gwinn's direct free kick salvaged a 1–1 draw.^[19] In the third match, Gwinn scored a goal in Germany's victory over Cameroon.^[20]

She played in the 2017 UEFA Women's Under-19 Championship (scoring a goal against Scotland^[21]) in Northern Ireland where she reached the semi-final and with this she qualified for the 2018 FIFA U-20 Women's World Cup (where scored a goal against China^[22] and was named "Player of the Match" against Nigeria^[23]).

Senior

On 14 May 2019, Gwinn was named to the 2019 FIFA Women's World Cup German squad.^[24] 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.^[25] The German World 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.^[26]