Blanketed by golden fields and thatched-roof houses along the Baltic coast, the Danish island of Ærø seems made for a serene summer escape. For Christine Kalis from Flensburg, however, it also became the place where her two children could receive the kind of education they cannot in their own country. Both, aged 9 and 12, are now homeschooled — permitted in Denmark but effectively banned in most cases in Germany.