Cassie did already think Spidey needed help because she knew who he was and in his position she figured she'd need some help, too. Even if he wanted to do it all alone, that was stupid. Even Cassie who would run off at the drop of a hat and defy authority knew there was safety in numbers, that you could manage more with friends, partners, a team then you ever could by yourself. Anyone who thought otherwise at a time like this was just stupid. She wasn't going to say any of this to Tony, though, because even mentioning going off to the Empire State Building would probably send him into a fit. She would just have to go and maybe come back before anyone found out and if she got stuck out there, she'd figure out a way to at least tell Tony for real this time so he didn't have to worry.
At his remark, talking to her like she was a little kid who didn't quite get it, Cassie snorted and quirked an eyebrow. "Yeah, like I didn't know that," she said flatly but she was at least smiling, choosing not to get all up in arms over his tone. She knew it was complicated and she knew it was all really messed up. Except, she'd never known Tony Stark, any version of Tony Stark, to admit something was complicated. He was the billionaire genius king of fixing complicated. That was kind of scary, thinking this was something even he couldn't fix or- worse- if he thought this was something he couldn't fix. There had to be a cure, right? Someone out there just needed to figure it out and all this time she'd kind of in the back of her mind been counting Tony as one of those someones, with all the other egg head scientists (who weren't quite as cool as he was) and military and S.H.I.E.L.D. people, maybe. Everyone was doing their best, huh? Maybe his best wasn't going as far as he hoped it would.
Abruptly she flung herself forward and was hugging him again. "Yeah, I know they are. I know you are." She drew back to look him in the face. "And, you know, thank you." Just in case no one else had said so. Cassie didn't have to know what he'd been up to, she knew he was trying his hardest, that was good enough for her.