OT: Youth Football Coaches

I was asked to coach my youngest two girls all girls NFL flag football team this year. The experience has been great 10/11 girls have taken to learning and trying hard even if they are not the most athletic all I ask is they try. My issue is I have one girl who doesn't try who for example had her hands in her sleeves yesterday and got drilled in the face by a ball thrown to her. She stands still on both offense and defense when we try and get her in the games.

The girls are kindergarten through 3rd so a lot of what we try to do is teach fundamentals. How do I reach this girls? (She is 2nd grade so not too little). Do I reach out to her parents? Just bench her during games unless it's a blowout?

Thanks #askTKP

*edit: to clear up some points. While this is a youth league and the lower division is not "competitive" thr keague as they move up is in some form. The winner of the 4/5 th grade and winner of 6,7,8 th grade divisions are eligible for NFL girl flag football tournaments, invites to NFL games camps. So we try and teach them and have fun especially lowest division it's not a normal rec only league. My policy with parents and kids was as long as they try they will play. I don't require them to be at any weekly practice just the practice we hold before the games each Sunday. We rotate on offense and defense and girls play numerous positions. The girl in question here has played all three games both offense and defense and attends one practice a week outside the Sunday one. She will run drills but when it comes to running plays in practice or games she doesn't participate and I'm having to ask other girls to cover for her on the field. I've tried talking to her one on one and she just says she doesn't feel like try and is is scared of the ball. This next game we are going to have her just play defense since she doesn't have to worry about talking a handoff, running routes or catching and see if single focusing will help. But long term I'm not sure what to say to her or her parents.