Don't get me wrong its a far cry from domestic terrorism in the sense of someone planning an attack, building bombs, writing manifestos, etc.
But she's still manifesting the criminal intent, taking the criminal action, being the cause of the proximate harm, being the aggressor, disregarding the safety of others and acting maliciously and recklessly.
Justifiable self defense doesn't require that the other person be a firebreathing dragon from legend, some monster out to grind your bones to make your bread. As long as the circumstances would put a reasonable person in fear for their life, lethal force can be justified to stop the attacker. In some cases that has been tragic comedies of errors where two well-intentioned people wound up shooting at each other when both have fear. In some cases, one person is a clear aggressor like a bank robber, but is still culpable under transferred intent for deaths or injuries that result from other people trying to stop them, like a cop shooting at them and missing and hitting a bystander.
And that's not just a legal standard, its a moral and logical one. This woman woke up and chose to stalk and harass ICE agents. She chose to obstruct and impede them, even though it was clearly criminal. And she chose to flee officers, and disregarded the safety of everyone around her. Maybe she chose to try to run down the officer and her lack of traction saved his life, maybe she chose to disregard his safety and was trying to turn past him and just clipped him. We live in a world of actions and consequences, she had already made her intentional choices at every step leading up to that moment and she caused the situation. It simply doesn't matter whether she was trying to flee or run someone down at that point, a reasonable person seeing a vehicle aimed at them and spinning its tires as a lunatic ignores police orders has every reason to open fire and neutralize the threat, and her consequences were no longer a judgment of the courts but of a bullet
the gap between moral and legal justifications for police actions is entirely the fault of police unions.
if a cop screws up in a clear way the shows they shouldnt be employed, but they cant be held liable criminally, the union will throw an absolute fit if they're fired.
this ice agent should be fired, but not prosecuted. but it wont happen. neither will. so anti-ICE gets a Mike Brown level martyr. and trump is unable to capitulate, so he'll try and make the agent a hero to combat the martyrdom. and it will now lead to more copycat style behavior, because loonies realize that blocking cops in might draw a nationwide news story. these are the same type people willing to throw rocks at ICE cars or sit down in traffic in protest. ICE didnt send a message, they cut a head off the hydra.