As I said, no judgement from me one way or another. Also we have no way of knowing what kind of contract she had or whether there was some kind of morality clause. Maybe this violated it. Maybe not.
All I was saying was that, whether right or wrong, employment can be terminated pretty much anywhere in the United States for any reason as long as it’s not a protected thing, which this almost certainly is not. So saying something is or isn’t a fireable offense probably needs some context. Because anything could be a fireable offense if the company thinks it is.