"Oh, I know Peggy - " Tony starts, expression bright, then immediately shuts his mouth. He's uncertain how much Steve knows, and he doesn't want to spill the beans when it really should be Peggy and Howard's job to sit Steve down and explain. Clearing his throat, he hastily searches for something to say that isn't horribly awkward like "she's basically my aunt" or some such comment.
"I've read all her files," is what he settles on, though that hardly sounds much better. "She's an excellent agent. I wouldn't want to put her in the field without asking the rest of the group, but if she'd like to help Pepper she'd be more than welcome."