Oh that’s why you couldn’t get past the start screen. Only iphone and ipad offer the option to use fitness+ without a watch, so if you can have your daughter airplay from one of those devices to the Apple TV instead of using the Fitness app on the apple tv itself then she will be able to do the yoga workouts without a watch with no problem. You might also be able to cast the videos to your TV using an HDMI cable if you’re running iOS/iPadOS 14.5 (not out yet, but available in public beta). If you have iOS 14.3 or 14.4, using the HDMI cable won’t work from any devices that have a lightning port (such as older/cheaper ipads and all iphones), but it will work from the newer iPads that came with a USB-C port. I hope this helps you.