Try framing your question better, because I was trying to figure out your question.
How long have you been a USC? If you yourself have been a USC for over three years, then your wife can apply for USC under the 3 year minus 90 days rule, provided she has been a GC holder for 3 years.
In order words, if you were sworn in as a USC on June 1, 2006 and she became a GC holder on Jan 1, 2007, she will be eligible for USC under the 3 year rule around Oct 2010. On June 1, 2010, you would have been a USC for 3 years, and she would be eligible on Oct 5 or someone around them...
I hope this helps...