Find out about the homeschooling support groups in your area. It is scary to take all this responsibility on yourself. Feel free to ask questions. You can do it, if you choose to. Learn everything you can to make an informed decision.
Parenthood is always a great adventure.
Continue to supplement her schoolwork where you feel she isn't challenged enough, and keep supplying her with great literature. I'm studying curriculum homepages and figuring out what I think will work for us. I know I'll make mistakes, but I'm willing to be flexible and change course as needed. I visit it everyday. Everyone here seems to have a genuine interest in each other, and they put much thought and care into their responses.