I only wanted to take a video of my children and post it on Instagram. I was on a train to Cornwall with my two youngsters — eight-year-old Lola and six-year-old Liberty — high above the river crossing the Tamar Bridge and under a glorious blue sky. Liberty struck a model pose, and all seemed fine. But when she saw me poised to publish the video to my Instagram, she demanded I stop. And, in the future, always ask for her permission first.