As both her and Jacen were in this world together now, they needed to co-exist. Which rested solely on Mara herself and what she chose to do. Between the two of them, from what she could sense through the Force and from what she'd gleaned from this conversation, Mara would be the aggressor if she chose the path of vengeance. But that was not a road for her, she would instead deal with it, let it go as much as she could, and move on. What other choice was there? She couldn't in good conscience kill her nephew now knowing that it wasn't Darth Caedus who stood there now. No, she would pull herself together and survive because that's what she did best. Mara adapted to her surroundings, and this was no different.
"As strange as it still feels to me, I am glad to be here, to be with you all again." Especially Anakin. Oh how she'd missed her youngest nephew. Truthfully, she'd missed all three of them, how they used to be. Jaina hadn't been the same after Anakin's death, and neither had Jacen. Perhaps she could do some good by being here. Perhaps she could strengthen their family bond again. She didn't have Luke or Ben here, so she'd instead turn those instincts to her niece and nephews if she could.
At the statement of whether she'd stop him if Darth Caedus returned, Mara nodded. "Yes, I would. I would not hesitate to stop you." She would do non-lethal means first and foremost, but she definitely would not fall for the assurances he was fine again. Jacen fooled her once, but Mara was not the type to be fooled twice by the same person. Of course she knew Caedus would always be part of Jacen and he would never truly be the man he'd been before he fell, but neither did she expect him to be. What she did expect, however, was that he would try to keep the darkness under control for his wife and child if for nothing else.
When asked if she'd found anything redeeming, she had no hesitation in what her reply was. The smile on his face was proof enough. "I have. And that is love." With that answer, Mara kept to her tune of surprising people, but it was so obvious to her. After all, hadn't love been something that had helped steer her away from the dark side? Of course she hadn't exactly known what she'd felt for Luke right away, but she knew the value of family, of loved ones, and the fact that Jacen had that, that he would do anything for them, was redeeming. Within reason, obviously, but love was a redeeming quality if someone let it be.