How to explain to my grandma she's not a trainer.?

is it grandmas horse? Cause if it is you can forget about having anything to say. Does grandma pay? Cause those who hold the financial burden hold the power, regardless of how much they know. If grandma isn't financially responsible for anything, why is she always there? Go when she doesn't go, or don't tell her your going. Or you could just tell her you want to take lessons, maybe she could go an watch the trainer teaching you and she could learn some things.