...at least for a year. Yay, but honestly, you'd have thought she was committing some terrible crime, the way the authorities have reacted.
And no, you don't have to convince the authorities that you will provide a suitable education when you deregister. You just have to hand in a letter.
Here's the deal: in law, parents are responsible for ensuring that their children receive a suitable education. The state only has to step in after the event, if it a suitable education isn't happening.
UPDATE: here's Kelly on the story.