Personally, I would have said support as well. I'm the kind of player who would set up fights by walling off the enemy (and hopefully incoming junglers), and I also think she'd do well in a side lane as her passive is a little broken up going down midlane. To add to the whole walling off enemies; you don't even have to go in. Just enter another move command and there you go. You're not in danger of surprise 1v3'ing.
I've seen plenty of jungle gameplay, but I'm not a jungle main. I've thought that her clear speed isn't on par with others. But again, what do I know? Additionally, she seems to have decent ap scalings, so she might end up going full mage when the meta hits. So I can't definitively say as precisely as I'd like to be that she'd be a toplane mage or a utility support or even a utility jungler.
Lastly, the reason I say "toplane" mage is returning to the passive. It probably feels a lot smoother running down the wall than those breaks in the midlane.
Those are my thoughts.