My husband and I surfed the Internet for eternity looking for the exact answers you're looking for. ( I also have similar views to your wife although I decided if we were going to provide a home and family for a child who has no one, I needed to swallow my pride and do what I had to do. And believe me, it's been HARD!) But, here's where we ended up:
http://www.childadoptionfunds.org/
We have establsihed a 501c3 charity for the exact purpose of providing a home for our child and will continue to raise funds after we bring him home so we can help others do the same. The catch is - IRS-wise - the child needs to be from a developing country (which is pretty much anywhere outside the U.S.) or needs to qualify as a special needs adoption in the U.S., which could range from handicaps to age to a sibling group.
If it's something you're interested in knowing more about, let me know. And maybe if your wife looked at the situation more from the point of view that she is doing something for the child moreso than herself, that might help her reconcile her feelings to a workable level. I can SO relate to where she is, though, because there are so many people more deserving than I. But when I think about a child somewhere who has NO ONE, who's more deserving than them?
Good luck and God Bless!