Sounds like I am in a minority here thinking she should finish what she started! Maybe I wrong.
What people are telling you that's hard to hear is that she just isn't ready for this sort of thing right now. You need to separate your feelings of responsibility from your daughter.
I feel like people are really coming down on me here though for even coaching her team. I am not coaching her because I am really intensely wanting her to be this awesome soccer player and I have really high expectations for her. I simply wanted to do something to help out in the community. I wanted to teach kids about good sportsmanship, teamwork, and maybe some skills. I am not some crazy hardcore coach pressuring my child to play!
Can you bring a babysitter with you if your dh can't be there?
I would recommend the book:
Kids, Parents & Power Struggles by Mary Sheedy Kurcinka
It's got a lot of the same information as her earlier book: Raising Your Spirited Child but it's a bit more up to date.
You might also read Playful Parenting. My stubborn intense (aka spirited) 6 year old responds really really well to playful things.