Taxes for income abroad (Munich)

Hi

I have a question about taxes and I cannot find an answer. I've searched forums here in Inter Nations, Google, Toytown Germany, a many other places and nobody seem to have asked or solved my question (perhaps it is too specific). So, I decided to post it here and maybe someone has had a similar situation. Here it is...

I'm in Germany with my wife and we are both from abroad. I'm here for work and she has a residence permit for family reunification (Familiennachzug). Although she doesn't work here in Germany, she has income from abroad and she regularly brings money to Germany. So, my question is whether or not we should take into account her income abroad for taxes purposes.

Also, should we change to tax category III / V, or should we both stay in category IV ? If we only take into account my income here in Germany, we would meet the requirements for category III / V. But if we have to take into account her income abroad, we would have to stay in category IV.

I would really appreciate any thoughts on this.

Hernando