Pretty much everyone can jungle these days. Any champion who can manage to roughly keep up in levels, has good utility (read: CC) for ganks, and can live on fairly little gold (since the jungle is always gold-starved) can be a decent jungler.
Sure, AP champions are generally very slow junglers at the start, but they can still be very strong if they get a chance to make good ganks and get a bit of gold.
Lux has a double snare, a slow, and a long-ranged ult which she can use to assist from in the jungle. Hardly the worst jungle pick ever.