Wow, bro, you have a lot on your plate. There are a lot of variables at play, so I'll try to be careful with whatever advice I can muster. Regarding your wife, the bible mentions that when a man takes a wife, he leaves his mother and father and cleaves unto her, and the two become one flesh. Just has he "leaves and cleaves", so should she. Part of the importance of this passage is the establishment of the principle that the spouse is the primary priority. As much as you desire to help your nephews, you must first make sure home is taken care of. They have a saying here in America "Happy wife=happy life". On the flip side, your wife should also be in support of your needs and desires. The key thing is to effectively communicate what's on your heart and come to a consensus regarding what you should do about your nephews. You guys should also find some common ground on the issue of children as well. Unfortunately, THAT discussion likely should have been had prior to marriage. Nonetheless, the two of you are now one and should approach decision-making as a unit.