Perhaps Daenerys should have been worried that Jaime might try to kill her as well. She was the last Targaryen after all. The last in a long line of a family with an extremely colored history. Yet at the same time she knew if Jaime had intended to kill her, he would've simply done so before even speaking to her. So at least for the current moment, she did not fear him running his sword through her as well.
Though if Jaime had thought he had done her a favor in killing her father and sending her into exile, she begged to differ. Growing up without a real home, always living in Viserys' cruel shadow, that had not been a life she would have picked for herself, but it had been that way until she'd married Drogo and been accepted within the Dothraki people. At Drogo's side, she'd finally found acceptance, a home. Even if the Dothraki were nomadic, she had people that accepted her and didn't treat her as though she were merely a bargaining tool like Viserys had turned her into. She knew that was what Viserys had used her for so he could get his army.
"You kill my father and trigger the murders of the rest of my family and subsequently cause me to grow up in exile, and you say it was a favour?" True or not, it was Jaime's action of killing her father that had started it all. Course, her father may have been killed even if Jaime hadn't done so first, but who truly would know? "We are far beyond apologies. I am the last Targaryen, the Dragon's Daughter. I do not seek an apology. I simply seek to reclaim what is rightfully mine." There was a harshness within her voice. She was very much the cold Targaryen in this moment. Her time under Dark's control had brought it out, and now meeting her father's murderer face-to-face was making it that much more apparent. Though for all the coldness she felt and was exuding, there was no madness within her. No, she was intelligent if still naive in many ways. And it was perhaps a deadlier combination within her than the cold cruelty and madness had been in her father.
Daenerys barely managed to hold back a scoff at Jaime's offer of a truce, but she knew he was correct. They were not within their world, the Iron Throne was not here. Neither of them could accomplish their goals here. All they could do was get along within this new world, this new war, and survive. It was a bit strange that Jaime chose to swear on his house and not on the gods, but Daenerys didn't really dwell on it. "As khaleesi of the Dothraki and the Mother of Dragons, I will do you no harm." She would hold to such an oath so long as Jaime didn't break his. If he took action against her, she would see retribution taken. This oath, however, didn't mean that she would drop her guard against Jaime. She would be a fool to completely trust his word. After all, he'd broken an oath before, who was to say he wouldn't break another?