My husband's aunt raised two children to whom she did not give birth and although she never formerly adopted them they are as much a part of our family as her biological son. Both of these "adopted" children are now grandmothers and are very curious about their biological families. I have their original birth certificates so I know the names of their parents, including the mothers' maiden names. Any advice you can provide about how to locate their birth families and about how to approach them once found would be greatly appreciated.