Good luck. I coached basketball for both my son and daughter, baseball (son) and flag football (son). Flag was the worst. Yet somehow I coached 3 separate teams because other parents knew it sucked and no one would step up. My first year was 2nd/3rd coed. It was the only year we had a decent team, yet during one game - a loss, not coincidentally - I counted EIGHT kids on our team that cried. No exaggeration. Only 1 of them was a girl (she cried every week).
My tip is coach them to use the sidelines on defense as a defender. Do not be that kid that chases the other team to the sidelines and then allows the ball carrier to cut back. My kid was particularly good at doing that.
Everyone wants the ball, everyone wants to play QB, and then when they go 3 and out or throw a pick, they cry. Especially Mary Jo.
I'd do it again, though, those are some good and funny memories.
Coaching hoops and baseball on the other hand was a blast.