For sure there have been! One famous one was Coach Irene Stewart who coached football 18 years at Sagerton. And I know she was not the only one either!
The way this happened was because of WWII there was a lack of men in these small towns to coach or even teach because they were off fighting mostly...so women had to step in and fill the void...and in some cases even high school kids on the team coached the football team...think about that happening today a high school player/coach!
At the West Texas Historical Association’s annul conference I presented my paper on the beginning of six-man football in Texas and afterwards there was time for some Q & A and one older man sitting in related a story of his buddy who played 6-man in high school in the Austin area during the war years and they too where coached by a woman.