That girl is running the team. Not the HC. Until he has the stones to step up and do what's best for the team the situation will continue to deteriorate. Unfortunately, it sounds like the HC did not set the tone from the start of the season and now the team is paying the price. It's hard to expect players/families to come back after seeing a player running the team instead of the the HC. I would expect to see this team disintegrate once the last game of the season is over.
I saw a unique or unusual one a few weeks ago, the coach had a pre game meeting with the "parents", and explained what was happening at this game, "he was playing to win" and the girls with the most experience were going to be playing, because some girls U12 had not shown satisfactory skill levels and if the parents did not start spending more time with the girls, playing catch on the side , they would not see much playing time, this is 10 games into a 25 game schedule.. Not exactly the real topic here, but a coach with Control.
Devils advocate here ...
Is it a rec league? If so, I think coming to practice and having a good attitude are all you need to be guaranteed playing time. Skill is irrelevant.
If this is a travel team, or one in which the players had to try out, then I'd want to know if this expectation (that players practice on their own) and this philosophy (playing time will be distributed in ways that maximizing winning) were expressed at the start.