You said she violated the law when they told her to get out of the car. But that was before the car even moved, so she wasn't putting any of the ICE agents in danger. And the only "law" she might have been violating, was a traffic violation, which wasn't even very effective because eleven vehicles went around her, including the SUV that Ross was driving.
As far as lawful orders. Since she committed no federal crime at the time she was ordered out of the car, that order was "illegal". The ICE agents have no authority over her if she wasn't in violation of federal law.