I wouldn't say she's an idiot. I mean, she's batshit crazy, for sure, but idiot? Not at all. In fact, I'd say she's pretty smart. Will a recount change anything? No. But it's not really supposed to. If there are questions about voter fraud (like, for example, the president-elect saying that "millions" of people voted illegally), then a recount is the best way to get to the bottom of it. If there really is evidence of Russian (or anyone else) hacking, this is the best way to uncover it. Again, highly unlikely, but why not do it? It's not like it's costing the taxpayer anything. It's not my money, and if it helps people come to term with the results, so be it.
More importantly, by spearheading this effort it keeps the Green party in the public eye. All the money she's raising can be used for building grassroots efforts, recruiting downballot candidates, etc. But I think there's something more personal going on here too. Jill Stein was taking a lot of heat from some progressives for spoiling Hillary Clinton's chances. She's this year's Ralph Nader. The margin in Wisconsin was about 10,000 votes; Jill Stein got 30,000. Now, there's no guarantee that those Stein votes would have gone to Clinton. But come on. Realistically, it is very likely that Stein's presence changed the outcome in Wisconsin and possibly other states. I think the recount effort is at least in part an attempt at image rehabilitation.
An idiot would be someone who claims massive voter fraud but doesn't think there should be a recount. 
