To be fair kids love this stuff, what I would say is put one of my follow along workouts on TV or your laptop and do it with her. Here is a link to my channel https://www.youtube.com/channel/UCudJy6TDE1HKN7hqkirUa_g?view_as=subscriber
I've started when I was 16 and that was the best decision of my life :D
RE: Quick Advise For People Under 16 That Want To Start Working Out