You should talk to an attorney ... if your wife won this year's lottery ... the visa must be issued and used before September 30 ... most likely it will be best to go home and attend the interview with her.
IMMIGRATION LAW PROFESSOR for 10 years -- LEGAL DISCLAIMER: This answer is offered for informational purposes only. It does not constitute an attorney-client relationship.
you should carefully navigate this situation because of timing and the fact that the visa must be issued in the fiscal year that she won. I am also unable to tell if your wife is also in the US as that would impact my answer.