Actually from age 12 I have set my own lessons alwaysconfused ( I got to GCSE standard then and decided to focus on particular things as it will benefit me more in the future).
Her first step should be the education otherwise website, they have very clear and concise information. Briefly though no-one needs any qualifications to home school and they can choose what to teach ( there is no set curriculem). They can even teach on a purely oral basis if they wish, as long as the child learns at a standard suited to it's needs. There is no need to even inform the local LHA that you are homeschooling as it's not a legal requirement but they can be very helpful sometimes. It's entirely her choice.
I would never have wished to go to school, I've enjoyed everything about my education because it was easy as it was geared specifically for me and as such it taught me the value of self discipline, how to plan, arrange and take forward a specific area of learning, what to do when I hit a brick wall of my own stupidity and how to work on my weaknesses as well as my strengths.
I'm sure it's not for everyone, but I have had only positive experiences in my own case.
If she'd like any further info I would be very happy to discuss it further but in the meantime here is the EO website for her to have a mooch through.
http://www.educationotherwise.net/