I wish you all the luck in the world, sweetie. I know how much you want that.

Have y'all given any consideration to adoption of a baby from someplace else (other than your sister, i mean)? I know it can be very expensive, but there are still public agencies where you could get your name on the list. The Edna Gladney home in Fort Worth is one that comes to mind, and I know there are others around the country.
Birth Parents Resource for Unplanned Pregnancy - Gladney Adoption Agency

Just something to think about. I was reading in Parenting magazine that sometimes when couples begin looking into the adoption process, they miraculously turn up pregnant.