12 year old wants to join our society's 6 am yoga batch. Everyone else in it is over fifty

The batch runs on the clubhouse terrace, Monday to Friday, with a teacher who has taught the same group for years. Our daughter went once with a neighbour, came back very pleased, and wants to go every day in the holidays. She says the aunties are 'nicer than PE'. The teacher is fine with it. My hesitation is mainly whether an adult class is pitched right for a 12 year old, the stretching especially, and whether she'll still want to go at 6 am in week three. I'm on call two nights a week and won't always be up to see her off. Has anyone's child joined an adult class like this?