Another alternative for you may be to supplement your daughter's school curriculum with a homeschooling curriculum. Contact your local or state homeschooling organizations for more information about this possibility. Many parents have chosen this alternative for their children and are happy to share their experiences with potential homeschoolers. We have homeschooling chats here at ParentsPlace, too, which will put you in touch with experienced homeschoolers. There are many resources on the Internet for homeschoolers, too.
Home computers are one of the greatest teaching tools available today.
There is a vast amount of software on the market, much of it high-quality software for children. Programs that require logical thinking can challenge all children. There are support groups out there for parents of gifted children, including chats at ParentsPlace. You may find some valuable advice and contacts in this chat. If your area has a monthly parenting resource guide, look for groups that might meet your needs.