*Club domestic league appearances and goals, correct as of 10:00, 1 August 2024 (UTC) ‡ National team caps and goals, correct as of 10:00, 1 August 2024 (UTC)
Schmitz started playing football in 2007 at the youth division of FC Germania Zündorf where she was the only girl on the team.[2]
Schmitz started her senior career in the 2008–09 season with newly formed Bayer 04 Leverkusen women's team, playing in the 2. Bundesliga Süd at the time.[3][4][5]
Being the first goalkeeper, Schmitz saw plenty of action at Bayer Leverkusen. She saw the team promoted to Bundesliga in the 2010–11 season.
During her time with Bayer Leverkusen, Schmitz was named best goalkeeper at the DFB-Hallenpokal in 2014 and 2015 and won that cup in 2015.[6][7]
In 2015, after a grand total of 121 league appearances for Bayer Leverkusen, 86 of which were in the Bundesliga, Schmitz signed a two-year contract with Bayer Leverkusen's Bundesliga rival 1. FFC Turbine Potsdam.[8][9][4][5]
After a total of four years at Turbine Potsdam and 69 Bundesliga appearances, Schmitz left Germany to join Montpellier HSC playing in the French Division 1. Féminine.[10][2]
Schmitz returned to Germany after four years in France, signing a two year contract with VfL Wolfsburg.[11][12][4]
The 2023–24 season was Schmitz's first experience not being the first goalkeeper of her team.[2] Nevertheless, Schmitz made four appearances with VfL Wolfsburg in the Bundesliga and further two appearances in the Champions League qualifiers against Paris FC.[5]