Our 39 year old daughter severely berated us for the looks we gave each other. How can I convince her that if/when the muslims are in the majority (here) that she and I will wear a burka or have our heads chopped off for disobeying?
Teach her about how muslims treat minorities. Tell her about every case of muslims kidnapping little Christian/jewish/hindu/sikh girls that you see on Jihadwatch etc. Eventually she might wake up to what islam really is.
You can’t teach her that islam is evil, but with enough examples of its evil she may realize it herself.