For frazzled parents, (or young people who have outgrown Cookie Monster!) you may be interested in tips from Sarah Rudell Beach, Executive Director of Brilliant Mindfulness, and a certified instructor for Mindful Schools in the USA. She has an excellent website – look out for her blog on teaching mindfulness techniques to teenagers.
Or you could try the 5 free Happiness Workouts in the  Happy, Not Perfect app; meditation for 13+ available for Apple and Android devices (in-app purchases but also free content).