Note that I'm not necessarily opposed to her facing consequences for killing him -- my issue is with how gleefully NYPost is framing it as if she just attacked him out of the blue and shoehorning her into the "evil transgenders" stereotype
Stabbing has always the risk of being fatal. No slur deserves death.
Edit: to expand to that, being motivated and proportional are two principles that I find very moral. I agree that legal and moral are not the same, but in this case I think the law is absolutely aligned with my moral. Stabbing someone for a slap or a slur is completely disproportionate and I would absolutely not consider it justified. Being assaulted and fearing from your life, that is different.