If she had, it would have been her admitting that she was wrong about the Federation, that she had made the wrong choice to embrace her Romulan heritage and shun all things about her that was human. That was the whole point of her 'patriotism.' Her actions were made on the basis of 'if we do not balance the field, the Federation, the humans, will use their advantage and wipe us out.' If she admitted that she was wrong, that the Federation wouldn't take that step and make a preemptive strike on the Empire, then she would be admitting that there was something about the Federation that was better than the Romulans, that they were genuine in their beliefs and attitudes of peaceful coexistence, and that meant that she had made the wrong choice in getting her mother killed and staying with her father and the Romulans. That was why being sent to the Federation was her fate worse than death - it would have been coming face to fact with the fact that she was wrong.