The Perils of Facetime

My daughter, Kimmie, has impeccable timing when it comes to iPhone/iPad Facetime. Tonight she called as I was stepping out of the shower. Not only do I have dripping hair and no make-up when she calls. I'm also naked. I felt the need to decline so my grandsons wouldn't go blind and be scarred for life.
But I'm curious. If I wear makeup for 14 hours a day, how does Kimmie know to call during those other 2 hours? It's always when I look the worse that she wants to request Facetime? And instead of the two inch face on my iPhone, I get to have a 10 inch face on her iPad.
And now you know why I didn't answer the phone naked!