I am a big fan of Mistress Gaia, I think her body is just otherworldly. Her threats of things like stomping with stilettos appear to be just part of the scene, I have also heard her threaten castration but I have never seen her do anything that would really harm or hurt the slave. Unless, of course, you include consuming her fecal material which happens in almost every clip.

There is one scene where she beats up a female slave but it looks like fantasy wrestling.

I don't know if many Mistresses would want to take the risk of trampling a slave in stilletos; perhaps if they were sitting down or balancing on one leg. But not full weight trampling.