This is being presented as a credited course in the school, like PE, math or science, not an after school program.
I understood the OP. Spirituality isn't going to be an accepted term even if it represents something other than a religious view as it elicits a religious mindset. Philosophy, as someone else mentioned would be a better choice of words. I would think that if she could get an official to watch a few practices and she has a specific curriculum to present it would go a long way in showing the establishment that what she was teaching wasn't religion oriented.