There are many correspondence and independent study programs that will help your daughter obtain an accredited diploma. I suggest you do some research and visit each school's site and see what program is most agreeable to you and your daughter. The Clonlara School is a good choice, and I know several teens who are very pleased with Clonlara's program. The American School is good for families who want a "school at home" type of program, based more on traditional course requirements. Cafi Cohen is a homeschooling mom and author of Homeschooling the Teen Years. I think you'll find this book an indispensable guide as you begin your new adventure. Be sure to read Homeschooling Teens and Leaving School and Learning at Home for more helpful suggestions. Best wishes to you and your daughter.
High-School Diploma for Homeschooler
Homeschooling Expert Advice from Isabel Shaw