Much of that was courtesy of the US and UK, who provided the free french with weapons, food, ammunition, armor, transportation, etc.
When France eventualy was liberated they only served as a reserve to the US and UK during the push into the Rhine
France resisted occupation, but they did so underground.
Not so fast.
The legendary 2nd French Armored Division, after the Liberation of Paris, fought in the tank battles in Lorraine, destroying the German 112th Panzer Brigade at the town of Dompaire on 13 September 1944.
Subsequently, the 2nd Division operated with U.S. forces during the assault into the Vosges Mountains. Serving as the armored exploitation force for the U.S. XV Corps, the 2nd Division forced the Saverne Gap and thrust forward boldly, unbalancing German defenses in northern Alsace and liberating Strasbourg on 23 November 1944. The Presidential Unit Citation was awarded to the Division for this action.
Fighting in Alsace until the end of February, 1945, the 2nd Division was deployed to reduce the Royan Pocket on the western coast of France in March-April, 1945.
After forcing the Germans in the Royan Pocket to surrender on 18 April 1945, the 2nd Division crossed France again to rejoin the Allied 6th Army Group for final operations in Germany. Operating with the U.S. 12th Armored Division, elements of the French 2nd Armored Division pursued the remnants of German Army Group G across Swabia and Bavaria, occupying the town of Bad Reichenhall on 4 May 1945.
Eventually, the 2nd Division finished its campaigning at the Nazi resort town of Berchtesgaden in Southeastern Germany.
At the end of the campaign in northwestern Europe, the unit counted 1,687 dead, including 108 officers, and 3,300 wounded. It had killed 12,100 Axis soldiers, captured 41,500 and destroyed 332 heavy and medium tanks, 2,200 other vehicles, and 426 cannons of various types.
Also, can't forget the Colmar Pocket in 20 January and 9 February 1945, where the French First Army and the U.S. XXI Corps overwhelmed German Nineteenth Army resistance in bitter, extremely cold winter fighting over terrain that offered practically no cover for attacking forces. French casualties were 13,000, US 8,000. Germans lost 22,000,probably high as 38,500.
Supplied by the Allies? Yes. As a reserve? Not the French First Army, the 2nd French Armored Division, or the FFI fighting scattered German remnants in France.