Yikes, actually, her voting might be considered part of the moral turptitude part...I think that's listed under 212 (a) (2)
(I) a crime involving moral turpitude (other than a purely political offense or an attempt or conspiracy to commit such a crime), or
Hmm. Whether voting by a non-U.S. citizen constitutes a crime of moral turpitude seems to be a really murky question.
Apparently there have been some decisions by the Board of Immigration Appeals saying that the act of registering to vote by a non-citizen does not constitute a crime of moral turpitude; see http://www.uscis.gov/ilink/docView/AFM/HTML/AFM/0-0-0-1/0-0-0-26573/0-0-0-40306/0-0-0-40345.html
However, actual voting is not mentioned there. So who knows...
You really need to talk to some lawyers about this.