She gave him a nod of encouragement when he confessed that she was trusted, and that meant more to her than she was willing to say. The day that Steve called her friend was a day that had changed her, and changing a woman like Natasha was a hard thing to do. In the end, the only thing that had changed about her when she switched sides was her hit list; she went from killing agents to killing terrorists, but her deep set beliefs were still the same. Trust no one but your superior, attachment was for fools and love was for children. Efficiency was the purpose of existence, and that was how it was. Until she met Steve.
It had nothing to do with emulating him. Natasha knew when something was out of her realm, lesson one had always been to know your limitations. Steve was too good, and Natasha had never fooled herself into thinking that she could be that righteous. There was too much blood on her hands. But to gain his trust, and his friendship, was still more than anything that she could have imagined herself worthy of doing, and that was why it was cherished. Steve was good. Maybe having a good person put their faith in her made her good too, to a certain degree, and her loyalties that day switched from SHIELD to him. They never left.
"We'll you're not getting rid of me any time soon, so that's good." It was partially a tease and partially a reassurance, but she meant it. In her opinion, being here with him was no more dangerous than being back home with him, their death was something that was always going to hang over their head, so why treat it differently now that they were in a different world? He managed to get a small smile out of her when he admitted that he missed her, but it quickly faded when his arm slipped it's way around her to drag her closer in a bold gesture that Steve had never done before. They rarely touched unless they nearly died and gave each other a relieved but thankful embrace, and when they touched beyond that it was due to her initiation. Not his.