She apologized and thanked you correcting her by pointing out to her that the term to use instead of Big Momma is plus-sized. Why do you think that she will continue using Big Momma after she expressed her gratitude to you for showing her the way?

And no, fat shaming and racial jokes aren't the same. Race is a protected category under federal and state law. You cannot discriminated based on race. Race is a long-standing protected category. Size, as of yet, is not a protected category. There is a big divide. You might feel the sting of being fat shamed, but it is not, yet, the kind of grievance that translates into a discrimination-based complaint under the current law. It might one day (but how do you define fat and fat shaming? a slippery slope) but currently it is not. San Fransisco is an exception but you are not in SF. "Only a few jurisdictions in California, including San Francisco, have a prohibition against height, weight, or size discrimination. In places where there are no such specific laws, you may be able to rely on general disability discrimination and harassment laws." But you are not disabled based on your size and I doubt that what you are describing rose to the level of harassment. By the way, you are saying that men would be sued for harassment based upon mere looks they give women. I do not think that the scope of harassment is as broad or as nebulous as to include mere looks.