No girls should play sports just not football if they are active. My sister complete opposite but Dad did see something different in me. I was 5'8 and into sports in high-school. My daughter 5'10 and oldest son 6'4. Don't tell them they can't play but let them play with girls even tho my daughter played T-ball and coach pitch with both. She was the only one who could throw the ball to first base from third. Then she went to softball-fastpitch. If she had no interest I would not have put her out there and she played basketball and volleyball. Put them in something even if it's girly. Builds self confidence.
We were playing the team in the next county, they had the distinction of kicking our asses every year. Some of the dudes on that team were my size, I almost considered checking their ages.
Anyway, we had some really small girls on the team and I told their parents that I would be keeping them out of the game just for the day in concern for their safety, but I'd double them up in the next game or two.
So we're getting trounced. I put my son in at goal, he's no skilled goalie but I figured he'd be good at getting the ball out of our end if needed. This dude on the other team, must have been 6' tall caught a breakaway. He's the only dude on our side of the field and he's barreling down on the goal - 1 on 1. I said nothing, my kid's on his own here - so what does he do? He bolts out of the goal toward this dude and takes him out - midfield tackle. That other kid was twice his size, dropped like a sack of hammers.
No card either, I thought for sure he'd get tossed.
I have one more story, I'm sure it gets old listening to kid stories but this one is ok.
I was coaching a game and my kid, pretty aggressive but not a great ball handler. Some of the other kids were going after the ball when he had it so he starts protecting the ball with his body and elbows. I didn't coach that, he just did it and the ref didn't seem to mind.
My wife is on the far side taking videos and she plays it back to me at home, tells me "you have to hear this parent from the other team". My son's number was 17 and I guess he was out there throwing his elbows around and this parent standing right next to my wife is yelling "GET THAT #17 OFF THE FIELD BEFORE HE KILLS SOMEONE!".
Then all I can hear is my wife chuckling on the video.