Genealogy / Mroz surname - adoption - searching for family members of my adopted Polish daughter [7]

I too am looking for the birth mother of our adopted children. We adopted in 2007 when our kids were 6 & 8, so they have vivid memories of their birth mother and their lives in Poland. Our situation is somewhat complicated, as our boys have 3 half-siblings that were adopted by another US couple in 2006. Recently we were notified of another sibling found in an orphanage in Warsaw. The other US couple is working towards adopting this child. We have a relationship w/the other US couple and are involved in their newest adoption. We thought that this new child might bring w/him additional information about Polish Mama. As of yet, it has not. It seems as though I have a wealth of information provided to us at the time of our adoption including birth parent names, last place of residence, birth place, birth dates, etc, but I have no idea how to make the info work for me short of going to Poland and knocking on doors. If anyone has info on how to get started on something like this, please let me know.