Online obsession

Today is d-day at whl, at long last. Left her alone at home and she spent the whole day playing Killer Sudoku online at http://www.killersudokuonline.com/ and despite spending the whole day playing puzzle weekly no:167 which is billed as mind-bending, she couldn't solve it without any hint and gave up after nearly getting a headache. Can't leave her alone at home at all.