I don't know if we can completely trust Felicity Jones isn't just misunderstanding the nuances of the question, but in this video, the rather lovely Jan Gilbert seems to trick her into confirming her Amazing Spider-Man 2 role.
And what's more, there might be a twinkle or two that we can construe as long term plans for the character. You know, while we're busy trying to decode body language in ways that don't really make sense.
Another interpretation of that wriggle might be:
But I'm already the Black Cat in this movie, I just can't say so.
Though I'm going to keep doubting that. At the very least, though, I think it's likely that Jones is playing Hardy.
They're really packing The Amazing Spider-Man 2 with villains, it seems. Or at least their aliases.
Incidentally, Gilbert's interview was done to support Drake Doremus' Breathe In which looks fantastic. I hope to see it soon.