Initially she had thought it was just her hardware, but Tony had come to help - to make sure that she wasn't going to end up purging memories that she needed to be the person she was now, or lose control while she was living here among so many Terrans. But with that taken care of it was obvious that her troubles were not entirely to do with her hardware malfunctioning.
She woke that morning feeling heavy in a way she was not used to - reminding her of the days she'd wake after Thanos had given her some new upgrade, all in his endless pursuit to make her better, to get her on the same level as Gamora. But it was not the kind of ache of a missing limb or new wires in her head, it was something more biological.
Walking slowly Nebula sat with Gamora after a moment, "I am not well." She agreed with a low sigh of annoyance of such a thing happening to her. To either of them.
"The Terrans have been getting sick," She told her. "It should not have effected us." Because they weren't of Earth, and they were both stronger than some kind of sick day. "You need to hydrate yourself."